90 KiB
7.0.0 - TBD
-
Reduced the library size. For example, on macOS the stripped binary statically linked with {fmt}
shrank from ~368k to less than 100k <http://www.zverovich.net/2020/05/21/reducing-library-size.html>
_. -
Added a simpler and more efficient
format string compilation API <https://fmt.dev/dev/api.html#compile-api>
_:.. code:: c++
#include <fmt/compile.h>
// Converts 42 into std::string using the most efficient method and no // runtime format string processing. std::string s = fmt::format(FMT_COMPILE("{}"), 42);
The old
fmt::compile
API is now deprecated. -
Optimized integer formatting:
format_to
with format string compilation and a stack-allocated buffer is nowfaster than to_chars on both libc++ and libstdc++ <http://www.zverovich.net/2020/06/13/fast-int-to-string-revisited.html>
_. -
Applied extern templates to improve compile times when using the core API and
fmt/format.h
(#1452
_). For example, on macOS with clang the compile time of a test TU dropped from 2.3s to 0.3s with-O2
and from 0.6s to 0.3s with the default settings (-O0
).Before (
-O2
)::% time c++ -c test.cc -I include -std=c++17 -O2 c++ -c test.cc -I include -std=c++17 -O2 2.22s user 0.08s system 99% cpu 2.311 total
After (
-O2
)::% time c++ -c test.cc -I include -std=c++17 -O2 c++ -c test.cc -I include -std=c++17 -O2 0.26s user 0.04s system 98% cpu 0.303 total
Before (default)::
% time c++ -c test.cc -I include -std=c++17 c++ -c test.cc -I include -std=c++17 0.53s user 0.06s system 98% cpu 0.601 total
After (default)::
% time c++ -c test.cc -I include -std=c++17 c++ -c test.cc -I include -std=c++17 0.24s user 0.06s system 98% cpu 0.301 total
It is still recommended to use
fmt/core.h
instead offmt/format.h
but the compile time difference is now smaller.Thanks
@alex3d <https://github.com/alex3d>
_ for the suggestion. -
Named arguments are now stored on stack (no dynamic memory allocations) and the generated binary code is more compact and efficient. For example
.. code:: c++
#include <fmt/core.h>
int main() { fmt::print("The answer is {answer}\n", fmt::arg("answer", 42)); }
compiles to just (
godbolt <https://godbolt.org/z/NcfEp_>
__).. code:: asm
.LC0: .string "answer" .LC1: .string "The answer is {answer}\n" main: sub rsp, 56 mov edi, OFFSET FLAT:.LC1 mov esi, 23 movabs rdx, 4611686018427387905 lea rax, [rsp+32] lea rcx, [rsp+16] mov QWORD PTR [rsp+8], 1 mov QWORD PTR [rsp], rax mov DWORD PTR [rsp+16], 42 mov QWORD PTR [rsp+32], OFFSET FLAT:.LC0 mov DWORD PTR [rsp+40], 0 call fmt::v6::vprint(fmt::v6::basic_string_view<char>, fmt::v6::format_args) xor eax, eax add rsp, 56 ret .L.str.1: .asciz "answer"
-
Implemented compile-time checks for dynamic width and precision (
#1614
_):.. code:: c++
#include <fmt/format.h>
int main() { fmt::print(FMT_STRING("{0:{1}}"), 42); }
now gives a compilation error because argument 1 doesn't exist::
In file included from test.cc:1: include/fmt/format.h:2726:27: error: constexpr variable 'invalid_format' must be initialized by a constant expression FMT_CONSTEXPR_DECL bool invalid_format = ^ ... include/fmt/core.h:569:26: note: in call to '&checker(s, {}).context_->on_error(&"argument not found"[0])' if (id >= num_args_) on_error("argument not found"); ^
-
Added sentinel support to
fmt::join
(#1689
_):.. code:: c++
struct zstring_sentinel {}; bool operator==(const char* p, zstring_sentinel) { return p == '\0'; } bool operator!=(const char p, zstring_sentinel) { return *p != '\0'; }
struct zstring { const char* p; const char* begin() const { return p; } zstring_sentinel end() const { return {}; } };
auto s = fmt::format("{}", fmt::join(zstring{"hello"}, "_")); // s == "h_e_l_l_o"
Thanks
@BRevzin (Barry Revzin) <https://github.com/BRevzin>
_. -
Added support for named args,
clear
andreserve
todynamic_format_arg_store
(#1655
,#1663
,#1674
,#1677
). Thanks@vsolontsov-ll (Vladimir Solontsov) <https://github.com/vsolontsov-ll>
_. -
Added support for the
'c'
format specifier to integral types for compatibility withstd::format
(#1652
_). -
Implemented the
'L'
format specifier for locale-specific formatting of floating-point numbers for compatibility withstd::format
(#1624
_). The'n'
specifier is now disabled by default but can be enabled via theFMT_DEPRECATED_N_SPECIFIER
macro. -
The
'='
format specifier is now disabled by default for compatibility withstd::format
. It can be enabled via theFMT_DEPRECATED_NUMERIC_ALIGN
macro. -
Optimized handling of small format strings. For example,
.. code:: c++
fmt::format("Result: {}: ({},{},{},{})", str1, str2, str3, str4, str5)
is now ~40% faster (
#1685
_). -
Improved compatibility between
fmt::printf
with the standard specs (#1595
,#1682
,#1683
,#1687
,#1699
,#1717
). Thanks@rimathia <https://github.com/rimathia>
_. -
Fixed handling of
operator<<` overloads that use
copyfmt`` (#1666
_). -
Removed the following deprecated APIs:
FMT_STRING_ALIAS
andfmt
macros - replaced byFMT_STRING
fmt::basic_string_view::char_type
- replaced byfmt::basic_string_view::value_type
convert_to_int
format_arg_store::types
*parse_context
- replaced by*format_parse_context
FMT_DEPRECATED_INCLUDE_OS
FMT_DEPRECATED_PERCENT
- incompatible withstd::format
*writer
- replaced by compiled format API
-
Deprecated
arg_formatter
. -
Renamed the
internal
namespace todetail
(#1538
_). The former is still provided as an alias if theFMT_USE_INTERNAL
macro is defined. -
Added the
FMT_OS
CMake option to control inclusion of OS-specific APIs in the fmt target. This can be useful for embedded platforms (#1654
,#1656
). Thanks@kwesolowski (Krzysztof Wesolowski) <https://github.com/kwesolowski>
_. -
Replaced
FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
with theFMT_FUZZ
macro to prevent interferring with fuzzing of projects using {fmt} (#1650
). Thanks@asraa (Asra Ali) <https://github.com/asraa>
. -
Fixed compatibility with emscripten (
#1736
,#1737
). Thanks@ArthurSonzogni (Arthur Sonzogni) <https://github.com/ArthurSonzogni>
_. -
Improved documentation (
#704
,#1643
,#1660
,#1681
,#1691
,#1706
,#1714
,#1721
,#1739
,#1740
,#1741
). Thanks@senior7515 (Alexander Gallego) <https://github.com/senior7515>
,@lsr0 (Lindsay Roberts) <https://github.com/lsr0>
,@puetzk (Kevin Puetz) <https://github.com/puetzk>
,@fpelliccioni (Fernando Pelliccioni) <https://github.com/fpelliccioni>
, Alexey Kuzmenko,@jelly (jelle van der Waa) <https://github.com/jelly>
,@claremacrae (Clare Macrae) <https://github.com/claremacrae>
,@jiapengwen (文佳鹏) <https://github.com/jiapengwen>
,@gsjaardema (Greg Sjaardema) <https://github.com/gsjaardema>
_. -
Implemented various build configuration fixes and improvements (
#1603
,#1657
,#1702
,#1728
). Thanks@scramsby (Scott Ramsby) <https://github.com/scramsby>
,@jtojnar (Jan Tojnar) <https://github.com/jtojnar>
,@orivej (Orivej Desh) <https://github.com/orivej>
,@flagarde <https://github.com/flagarde>
. -
Fixed various warnings and compilation issues (
#1616
,#1620
,#1622
,#1625
,#1627
,#1628
,#1629
,#1631
,#1633
,#1649
,#1658
,#1661
,#1667
,#1668
,#1669
,#1692
,#1696
,#1697
,#1707
,#1712
,#1716
,#1722
,#1724
,#1729
,#1738
,#1742
,#1743
,#1744
,#1747
,#1750
). Thanks@gsjaardema (Greg Sjaardema) <https://github.com/gsjaardema>
,@gabime (Gabi Melman) <https://github.com/gabime>
,@johnor (Johan) <https://github.com/johnor>
,@gabime (Dmitry Kurkin) <https://github.com/Kurkin>
,@invexed (James Beach) <https://github.com/invexed>
,@peterbell10 <https://github.com/peterbell10>
,@daixtrose (Markus Werle) <https://github.com/daixtrose>
,@petrutlucian94 (Lucian Petrut) <https://github.com/petrutlucian94>
,@Neargye (Daniil Goncharov) <https://github.com/Neargye>
,@ambitslix (Attila M. Szilagyi) <https://github.com/ambitslix>
,@gabime (Gabi Melman) <https://github.com/gabime>
,@erthink (Leonid Yuriev) <https://github.com/erthink>
,@tohammer (Tobias Hammer ) <https://github.com/tohammer>
,@0x8000-0000 (Florin Iucha) <https://github.com/0x8000-0000>
.
6.2.1 - 2020-05-09
-
Fixed ostream support in
sprintf
(#1631
_). -
Fixed type detection when using implicit conversion to
string_view
and ostreamoperator<<
inconsistently (#1662
_).
6.2.0 - 2020-04-05
-
Improved error reporting when trying to format an object of a non-formattable type:
.. code:: c++
fmt::format("{}", S());
now gives::
include/fmt/core.h:1015:5: error: static_assert failed due to requirement 'formattable' "Cannot format argument. To make type T formattable provide a formatter specialization: https://fmt.dev/latest/api.html#formatting-user-defined-types" static_assert( ^ ... note: in instantiation of function template specialization 'fmt::v6::format<char [3], S, char>' requested here fmt::format("{}", S()); ^
if
S
is not formattable. -
Reduced the library size by ~10%.
-
Always print decimal point if
#
is specified (#1476
,#1498
):.. code:: c++
fmt::print("{:#.0f}", 42.0);
now prints
42.
-
Implemented the
'L'
specifier for locale-specific numeric formatting to improve compatibility withstd::format
. The'n'
specifier is now deprecated and will be removed in the next major release. -
Moved OS-specific APIs such as
windows_error
fromfmt/format.h
tofmt/os.h
. You can defineFMT_DEPRECATED_INCLUDE_OS
to automatically includefmt/os.h
fromfmt/format.h
for compatibility but this will be disabled in the next major release. -
Added precision overflow detection in floating-point formatting.
-
Implemented detection of invalid use of
fmt::arg
. -
Used
type_identity
to block unnecessary template argument deduction. Thanks Tim Song. -
Improved UTF-8 handling (
#1109
_):.. code:: c++
fmt::print("┌{0:─^{2}}┐\n" "│{1: ^{2}}│\n" "└{0:─^{2}}┘\n", "", "Привет, мир!", 20);
now prints::
┌────────────────────┐ │ Привет, мир! │ └────────────────────┘
on systems that support Unicode.
-
Added experimental dynamic argument storage (
#1170
,#1584
):.. code:: c++
fmt::dynamic_format_arg_storefmt::format_context store; store.push_back("answer"); store.push_back(42); fmt::vprint("The {} is {}.\n", store);
prints::
The answer is 42.
Thanks
@vsolontsov-ll (Vladimir Solontsov) <https://github.com/vsolontsov-ll>
_. -
Made
fmt::join
acceptinitializer_list
(#1591
). Thanks@Rapotkinnik (Nikolay Rapotkin) <https://github.com/Rapotkinnik>
. -
Fixed handling of empty tuples (
#1588
_). -
Fixed handling of output iterators in
format_to_n
(#1506
_). -
Fixed formatting of
std::chrono::duration
types to wide output (#1533
). Thanks@zeffy (pilao) <https://github.com/zeffy>
. -
Added const
begin
andend
overload to buffers (#1553
). Thanks@dominicpoeschko <https://github.com/dominicpoeschko>
. -
Added the ability to disable floating-point formatting via
FMT_USE_FLOAT
,FMT_USE_DOUBLE
andFMT_USE_LONG_DOUBLE
macros for extremely memory-constrained embedded system (#1590
). Thanks@albaguirre (Alberto Aguirre) <https://github.com/albaguirre>
. -
Made
FMT_STRING
work withconstexpr
string_view
(#1589
). Thanks@scramsby (Scott Ramsby) <https://github.com/scramsby>
. -
Implemented a minor optimization in the format string parser (
#1560
). Thanks@IkarusDeveloper <https://github.com/IkarusDeveloper>
. -
Improved attribute detection (
#1469
,#1475
,#1576
). Thanks@federico-busato (Federico) <https://github.com/federico-busato>
,@chronoxor (Ivan Shynkarenka) <https://github.com/chronoxor>
,@refnum <https://github.com/refnum>
. -
Improved documentation (
#1481
,#1523
). Thanks@JackBoosY (Jack·Boos·Yu) <https://github.com/JackBoosY>
,@imba-tjd (谭九鼎) <https://github.com/imba-tjd>
. -
Fixed symbol visibility on Linux when compiling with
-fvisibility=hidden
(#1535
). Thanks@milianw (Milian Wolff) <https://github.com/milianw>
. -
Implemented various build configuration fixes and improvements (
#1264
,#1460
,#1534
,#1536
,#1545
,#1546
,#1566
,#1582
,#1597
,#1598
). Thanks@ambitslix (Attila M. Szilagyi) <https://github.com/ambitslix>
,@jwillikers (Jordan Williams) <https://github.com/jwillikers>
,@stac47 (Laurent Stacul) <https://github.com/stac47>
_. -
Fixed various warnings and compilation issues (
#1433
,#1461
,#1470
,#1480
,#1485
,#1492
,#1493
,#1504
,#1505
,#1512
,#1515
,#1516
,#1518
,#1519
,#1520
,#1521
,#1522
,#1524
,#1530
,#1531
,#1532
,#1539
,#1547
,#1548
,#1554
,#1567
,#1568
,#1569
,#1571
,#1573
,#1575
,#1581
,#1583
,#1586
,#1587
,#1594
,#1596
,#1604
,#1606
,#1607
,#1609
). Thanks@marti4d (Chris Martin) <https://github.com/marti4d>
,@iPherian <https://github.com/iPherian>
,@parkertomatoes <https://github.com/parkertomatoes>
,@gsjaardema (Greg Sjaardema) <https://github.com/gsjaardema>
,@chronoxor (Ivan Shynkarenka) <https://github.com/chronoxor>
,@DanielaE (Daniela Engert) <https://github.com/DanielaE>
,@torsten48 <https://github.com/torsten48>
,@tohammer (Tobias Hammer) <https://github.com/tohammer>
,@lefticus (Jason Turner) <https://github.com/lefticus>
,@ryusakki (Haise) <https://github.com/ryusakki>
,@adnsv (Alex Denisov) <https://github.com/adnsv>
,@fghzxm <https://github.com/fghzxm>
,@refnum <https://github.com/refnum>
,@pramodk (Pramod Kumbhar) <https://github.com/pramodk>
,@Spirrwell <https://github.com/Spirrwell>
,@scramsby (Scott Ramsby) <https://github.com/scramsby>
_.
6.1.2 - 2019-12-11
-
Fixed ABI compatibility with
libfmt.so.6.0.0
(#1471
_). -
Fixed handling types convertible to
std::string_view
(#1451
). Thanks@denizevrenci (Deniz Evrenci) <https://github.com/denizevrenci>
. -
Made CUDA test an opt-in enabled via the
FMT_CUDA_TEST
CMake option. -
Fixed sign conversion warnings (
#1440
). Thanks@0x8000-0000 (Florin Iucha) <https://github.com/0x8000-0000>
.
6.1.1 - 2019-12-04
-
Fixed shared library build on Windows (
#1443
,#1445
,#1446
,#1450
). Thanks@egorpugin (Egor Pugin) <https://github.com/egorpugin>
,@bbolli (Beat Bolli) <https://github.com/bbolli>
. -
Added a missing decimal point in exponent notation with trailing zeros.
-
Removed deprecated
format_arg_store::TYPES
.
6.1.0 - 2019-12-01
-
{fmt} now formats IEEE 754
float
anddouble
using the shortest decimal representation with correct rounding by default:.. code:: c++
#include #include <fmt/core.h>
int main() { fmt::print("{}", M_PI); }
prints
3.141592653589793
. -
Made the fast binary to decimal floating-point formatter the default, simplified it and improved performance. {fmt} is now 15 times faster than libc++'s
std::ostringstream
, 11 times faster thanprintf
and 10% faster than double-conversion ondtoa-benchmark <https://github.com/fmtlib/dtoa-benchmark>
_:================== ========= ======= Function Time (ns) Speedup ================== ========= ======= ostringstream 1,346.30 1.00x ostrstream 1,195.74 1.13x sprintf 995.08 1.35x doubleconv 99.10 13.59x fmt 88.34 15.24x ================== ========= =======
.. image:: https://user-images.githubusercontent.com/576385/ 69767160-cdaca400-112f-11ea-9fc5-347c9f83caad.png
-
{fmt} no longer converts
float
arguments todouble
. In particular this improves the default (shortest) representation of floats and makesfmt::format
consistent withstd::format
specs (#1336
,#1353
,#1360
,#1361
):.. code:: c++
fmt::print("{}", 0.1f);
prints
0.1
instead of0.10000000149011612
.Thanks
@orivej (Orivej Desh) <https://github.com/orivej>
_. -
Made floating-point formatting output consistent with
printf
/iostreams (#1376
,#1417
). -
Added support for 128-bit integers (
#1287
_):.. code:: c++
fmt::print("{}", std::numeric_limits<__int128_t>::max());
prints
170141183460469231731687303715884105727
.Thanks
@denizevrenci (Deniz Evrenci) <https://github.com/denizevrenci>
_. -
The overload of
print
that takestext_style
is now atomic, i.e. the output from different threads doesn't interleave (#1351
). Thanks@tankiJong (Tanki Zhang) <https://github.com/tankiJong>
. -
Made compile time in the header-only mode ~20% faster by reducing the number of template instantiations.
wchar_t
overload ofvprint
was moved fromfmt/core.h
tofmt/format.h
. -
Added an overload of
fmt::join
that works with tuples (#1322
,#1330
):.. code:: c++
#include #include <fmt/ranges.h>
int main() { std::tuple<char, int, float> t{'a', 1, 2.0f}; fmt::print("{}", t); }
prints
('a', 1, 2.0)
.Thanks
@jeremyong (Jeremy Ong) <https://github.com/jeremyong>
_. -
Changed formatting of octal zero with prefix from "00" to "0":
.. code:: c++
fmt::print("{:#o}", 0);
prints
0
. -
The locale is now passed to ostream insertion (
<<
) operators (#1406
_):.. code:: c++
#include <fmt/locale.h> #include <fmt/ostream.h>
struct S { double value; };
std::ostream& operator<<(std::ostream& os, S s) { return os << s.value; }
int main() { auto s = fmt::format(std::locale("fr_FR.UTF-8"), "{}", S{0.42}); // s == "0,42" }
Thanks
@dlaugt (Daniel Laügt) <https://github.com/dlaugt>
_. -
Locale-specific number formatting now uses grouping (
#1393
,#1394
). Thanks@skrdaniel <https://github.com/skrdaniel>
_. -
Fixed handling of types with deleted implicit rvalue conversion to
const char**
(#1421
_):.. code:: c++
struct mystring { operator const char*() const&; operator const char*() &; operator const char*() const&& = delete; operator const char*() && = delete; }; mystring str; fmt::print("{}", str); // now compiles
-
Enums are now mapped to correct underlying types instead of
int
(#1286
). Thanks@agmt (Egor Seredin) <https://github.com/agmt>
. -
Enum classes are no longer implicitly converted to
int
(#1424
_). -
Added
basic_format_parse_context
for consistency with C++20std::format
and deprecatedbasic_parse_context
. -
Fixed handling of UTF-8 in precision (
#1389
,#1390
). Thanks@tajtiattila (Attila Tajti) <https://github.com/tajtiattila>
_. -
{fmt} can now be installed on Linux, macOS and Windows with
Conda <https://docs.conda.io/en/latest/>
__ using itsconda-forge <https://conda-forge.org>
__package <https://github.com/conda-forge/fmt-feedstock>
__ (#1410
_)::conda install -c conda-forge fmt
Thanks
@tdegeus (Tom de Geus) <https://github.com/tdegeus>
_. -
Added a CUDA test (
#1285
,#1317
). Thanks@luncliff (Park DongHa) <https://github.com/luncliff>
_ and@risa2000 <https://github.com/risa2000>
_. -
Improved documentation (
#1276
,#1291
,#1296
,#1315
,#1332
,#1337
,#1395
_#1418
). Thanks@waywardmonkeys (Bruce Mitchener) <https://github.com/waywardmonkeys>
,@pauldreik (Paul Dreik) <https://github.com/pauldreik>
,@jackoalan (Jack Andersen) <https://github.com/jackoalan>
. -
Various code improvements (
#1358
,#1407
). Thanks@orivej (Orivej Desh) <https://github.com/orivej>
,@dpacbach (David P. Sicilia) <https://github.com/dpacbach>
, -
Fixed compile-time format string checks for user-defined types (
#1292
_). -
Worked around a false positive in
unsigned-integer-overflow
sanitizer (#1377
_). -
Fixed various warnings and compilation issues (
#1273
,#1278
,#1280
,#1281
,#1288
,#1290
,#1301
,#1305
,#1306
,#1309
,#1312
,#1313
,#1316
,#1319
,#1320
,#1326
,#1328
,#1344
,#1345
,#1347
,#1349
,#1354
,#1362
,#1366
,#1364
,#1370
,#1371
,#1385
,#1388
,#1397
,#1414
,#1416
,#1422
_#1427
,#1431
,#1433
). Thanks@hhb <https://github.com/hhb>
,@gsjaardema (Greg Sjaardema) <https://github.com/gsjaardema>
,@gabime (Gabi Melman) <https://github.com/gabime>
,@neheb (Rosen Penev) <https://github.com/neheb>
,@vedranmiletic (Vedran Miletić) <https://github.com/vedranmiletic>
,@dkavolis (Daumantas Kavolis) <https://github.com/dkavolis>
,@mwinterb <https://github.com/mwinterb>
,@orivej (Orivej Desh) <https://github.com/orivej>
,@denizevrenci (Deniz Evrenci) <https://github.com/denizevrenci>
@leonklingele <https://github.com/leonklingele>
,@chronoxor (Ivan Shynkarenka) <https://github.com/chronoxor>
,@kent-tri <https://github.com/kent-tri>
,@0x8000-0000 (Florin Iucha) <https://github.com/0x8000-0000>
,@marti4d (Chris Martin) <https://github.com/marti4d>
_.
6.0.0 - 2019-08-26
-
Switched to the
MIT license <https://github.com/fmtlib/fmt/blob/5a4b24613ba16cc689977c3b5bd8274a3ba1dd1f/LICENSE.rst>
_ with an optional exception that allows distributing binary code without attribution. -
Floating-point formatting is now locale-independent by default:
.. code:: c++
#include #include <fmt/core.h>
int main() { std::locale::global(std::locale("ru_RU.UTF-8")); fmt::print("value = {}", 4.2); }
prints "value = 4.2" regardless of the locale.
For locale-specific formatting use the
n
specifier:.. code:: c++
std::locale::global(std::locale("ru_RU.UTF-8")); fmt::print("value = {:n}", 4.2);
prints "value = 4,2".
-
Added an experimental Grisu floating-point formatting algorithm implementation (disabled by default). To enable it compile with the
FMT_USE_GRISU
macro defined to 1:.. code:: c++
#define FMT_USE_GRISU 1 #include <fmt/format.h>
auto s = fmt::format("{}", 4.2); // formats 4.2 using Grisu
With Grisu enabled, {fmt} is 13x faster than
std::ostringstream
(libc++) and 10x faster thansprintf
ondtoa-benchmark <https://github.com/fmtlib/dtoa-benchmark>
_ (full results <https://fmt.dev/unknown_mac64_clang10.0.html>
_):.. image:: https://user-images.githubusercontent.com/576385/ 54883977-9fe8c000-4e28-11e9-8bde-272d122e7c52.jpg
-
Separated formatting and parsing contexts for consistency with
C++20 std::format <http://eel.is/c++draft/format>
_, removing the undocumentedbasic_format_context::parse_context()
function. -
Added
oss-fuzz <https://github.com/google/oss-fuzz>
_ support (#1199
). Thanks@pauldreik (Paul Dreik) <https://github.com/pauldreik>
. -
formatter
specializations now always take precedence overoperator<<
(#952
_):.. code:: c++
#include #include <fmt/ostream.h>
struct S {};
std::ostream& operator<<(std::ostream& os, S) { return os << 1; }
template <> struct fmt::formatter
: fmt::formatter { auto format(S, format_context& ctx) { return formatter::format(2, ctx); } };int main() { std::cout << S() << "\n"; // prints 1 using operator<< fmt::print("{}\n", S()); // prints 2 using formatter }
-
Introduced the experimental
fmt::compile
function that does format string compilation (#618
,#1169
,#1171
_):.. code:: c++
#include <fmt/compile.h>
auto f = fmt::compile("{}"); std::string s = fmt::format(f, 42); // can be called multiple times to // format different values // s == "42"
It moves the cost of parsing a format string outside of the format function which can be beneficial when identically formatting many objects of the same types. Thanks
@stryku (Mateusz Janek) <https://github.com/stryku>
_. -
Added experimental
%
format specifier that formats floating-point values as percentages (#1060
,#1069
,#1071
_):.. code:: c++
auto s = fmt::format("{:.1%}", 0.42); // s == "42.0%"
Thanks
@gawain-bolton (Gawain Bolton) <https://github.com/gawain-bolton>
_. -
Implemented precision for floating-point durations (
#1004
,#1012
):.. code:: c++
auto s = fmt::format("{:.1}", std::chrono::duration(1.234)); // s == 1.2s
Thanks
@DanielaE (Daniela Engert) <https://github.com/DanielaE>
_. -
Implemented
chrono
format specifiers%Q
and%q
that give the value and the unit respectively (#1019
_):.. code:: c++
auto value = fmt::format("{:%Q}", 42s); // value == "42" auto unit = fmt::format("{:%q}", 42s); // unit == "s"
Thanks
@DanielaE (Daniela Engert) <https://github.com/DanielaE>
_. -
Fixed handling of dynamic width in chrono formatter:
.. code:: c++
auto s = fmt::format("{0:{1}%H:%M:%S}", std::chrono::seconds(12345), 12); // ^ width argument index ^ width // s == "03:25:45 "
Thanks Howard Hinnant.
-
Removed deprecated
fmt/time.h
. Usefmt/chrono.h
instead. -
Added
fmt::format
andfmt::vformat
overloads that taketext_style
(#993
,#994
):.. code:: c++
#include <fmt/color.h>
std::string message = fmt::format(fmt::emphasis::bold | fg(fmt::color::red), "The answer is {}.", 42);
Thanks
@Naios (Denis Blank) <https://github.com/Naios>
_. -
Removed the deprecated color API (
print_colored
). Use the new API, namelyprint
overloads that taketext_style
instead. -
Made
std::unique_ptr
andstd::shared_ptr
formattable as pointers viafmt::ptr
(#1121
_):.. code:: c++
std::unique_ptr p = ...; fmt::print("{}", fmt::ptr(p)); // prints p as a pointer
Thanks
@sighingnow (Tao He) <https://github.com/sighingnow>
_. -
Made
print
andvprint
report I/O errors (#1098
,#1099
). Thanks@BillyDonahue (Billy Donahue) <https://github.com/BillyDonahue>
_. -
Marked deprecated APIs with the
[[deprecated]]
attribute and removed internal uses of deprecated APIs (#1022
). Thanks@eliaskosunen (Elias Kosunen) <https://github.com/eliaskosunen>
. -
Modernized the codebase using more C++11 features and removing workarounds. Most importantly,
buffer_context
is now an alias template, so usebuffer_context<T>
instead ofbuffer_context<T>::type
. These features require GCC 4.8 or later. -
formatter
specializations now always take precedence over implicit conversions toint
and the undocumentedconvert_to_int
trait is now deprecated. -
Moved the undocumented
basic_writer
,writer
, andwwriter
types to theinternal
namespace. -
Removed deprecated
basic_format_context::begin()
. Useout()
instead. -
Disallowed passing the result of
join
as an lvalue to prevent misuse. -
Refactored the undocumented structs that represent parsed format specifiers to simplify the API and allow multibyte fill.
-
Moved SFINAE to template parameters to reduce symbol sizes.
-
Switched to
fputws
for writing wide strings so that it's no longer required to call_setmode
on Windows (#1229
,#1243
). Thanks@jackoalan (Jack Andersen) <https://github.com/jackoalan>
_. -
Improved literal-based API (
#1254
). Thanks@sylveon (Charles Milette) <https://github.com/sylveon>
. -
Added support for exotic platforms without
uintptr_t
such as IBM i (AS/400) which has 128-bit pointers and only 64-bit integers (#1059
_). -
Added
Sublime Text syntax highlighting config <https://github.com/fmtlib/fmt/blob/master/support/C%2B%2B.sublime-syntax>
_ (#1037
). Thanks@Kronuz (Germán Méndez Bravo) <https://github.com/Kronuz>
. -
Added the
FMT_ENFORCE_COMPILE_STRING
macro to enforce the use of compile-time format strings (#1231
). Thanks@jackoalan (Jack Andersen) <https://github.com/jackoalan>
. -
Stopped setting
CMAKE_BUILD_TYPE
if {fmt} is a subproject (#1081
_). -
Various build improvements (
#1039
,#1078
,#1091
,#1103
,#1177
). Thanks@luncliff (Park DongHa) <https://github.com/luncliff>
,@jasonszang (Jason Shuo Zang) <https://github.com/jasonszang>
,@olafhering (Olaf Hering) <https://github.com/olafhering>
,@Lecetem <https://github.com/Lectem>
,@pauldreik (Paul Dreik) <https://github.com/pauldreik>
. -
Improved documentation (
#1049
,#1051
,#1083
,#1113
,#1114
,#1146
,#1180
,#1250
,#1252
,#1265
). Thanks@mikelui (Michael Lui) <https://github.com/mikelui>
,@foonathan (Jonathan Müller) <https://github.com/foonathan>
,@BillyDonahue (Billy Donahue) <https://github.com/BillyDonahue>
,@jwakely (Jonathan Wakely) <https://github.com/jwakely>
,@kaisbe (Kais Ben Salah) <https://github.com/kaisbe>
,@sdebionne (Samuel Debionne) <https://github.com/sdebionne>
. -
Fixed ambiguous formatter specialization in
fmt/ranges.h
(#1123
_). -
Fixed formatting of a non-empty
std::filesystem::path
which is an infinitely deep range of its components (#1268
_). -
Fixed handling of general output iterators when formatting characters (
#1056
,#1058
). Thanks@abolz (Alexander Bolz) <https://github.com/abolz>
_. -
Fixed handling of output iterators in
formatter
specialization for ranges (#1064
_). -
Fixed handling of exotic character types (
#1188
_). -
Made chrono formatting work with exceptions disabled (
#1062
_). -
Fixed DLL visibility issues (
#1134
,#1147
). Thanks@denchat <https://github.com/denchat>
_. -
Disabled the use of UDL template extension on GCC 9 (
#1148
_). -
Removed misplaced
format
compile-time checks fromprintf
(#1173
_). -
Fixed issues in the experimental floating-point formatter (
#1072
,#1129
,#1153
,#1155
,#1210
,#1222
). Thanks@alabuzhev (Alex Alabuzhev) <https://github.com/alabuzhev>
_. -
Fixed bugs discovered by fuzzing or during fuzzing integration (
#1124
,#1127
,#1132
,#1135
,#1136
,#1141
,#1142
,#1178
,#1179
,#1194
). Thanks@pauldreik (Paul Dreik) <https://github.com/pauldreik>
_. -
Fixed building tests on FreeBSD and Hurd (
#1043
). Thanks@jackyf (Eugene V. Lyubimkin) <https://github.com/jackyf>
. -
Fixed various warnings and compilation issues (
#998
,#1006
,#1008
,#1011
,#1025
,#1027
,#1028
,#1029
,#1030
,#1031
,#1054
,#1063
,#1068
,#1074
,#1075
,#1079
,#1086
,#1088
,#1089
,#1094
,#1101
,#1102
,#1105
,#1107
,#1115
,#1117
,#1118
,#1120
,#1123
,#1139
,#1140
,#1143
,#1144
,#1150
,#1151
,#1152
,#1154
,#1156
,#1159
,#1175
,#1181
,#1186
,#1187
,#1191
,#1197
,#1200
,#1203
,#1205
,#1206
,#1213
,#1214
,#1217
,#1228
,#1230
,#1232
,#1235
,#1236
,#1240
). Thanks@DanielaE (Daniela Engert) <https://github.com/DanielaE>
,@mwinterb <https://github.com/mwinterb>
,@eliaskosunen (Elias Kosunen) <https://github.com/eliaskosunen>
,@morinmorin <https://github.com/morinmorin>
,@ricco19 (Brian Ricciardelli) <https://github.com/ricco19>
,@waywardmonkeys (Bruce Mitchener) <https://github.com/waywardmonkeys>
,@chronoxor (Ivan Shynkarenka) <https://github.com/chronoxor>
,@remyabel <https://github.com/remyabel>
,@pauldreik (Paul Dreik) <https://github.com/pauldreik>
,@gsjaardema (Greg Sjaardema) <https://github.com/gsjaardema>
,@rcane (Ronny Krüger) <https://github.com/rcane>
,@mocabe <https://github.com/mocabe>
,@denchat <https://github.com/denchat>
,@cjdb (Christopher Di Bella) <https://github.com/cjdb>
,@HazardyKnusperkeks (Björn Schäpers) <https://github.com/HazardyKnusperkeks>
,@vedranmiletic (Vedran Miletić) <https://github.com/vedranmiletic>
,@jackoalan (Jack Andersen) <https://github.com/jackoalan>
,@DaanDeMeyer (Daan De Meyer) <https://github.com/DaanDeMeyer>
,@starkmapper (Mark Stapper) <https://github.com/starkmapper>
_.
5.3.0 - 2018-12-28
-
Introduced experimental chrono formatting support:
.. code:: c++
#include <fmt/chrono.h>
int main() { using namespace std::literals::chrono_literals; fmt::print("Default format: {} {}\n", 42s, 100ms); fmt::print("strftime-like format: {:%H:%M:%S}\n", 3h + 15min + 30s); }
prints::
Default format: 42s 100ms strftime-like format: 03:15:30
-
Added experimental support for emphasis (bold, italic, underline, strikethrough), colored output to a file stream, and improved colored formatting API (
#961
,#967
,#973
_):.. code:: c++
#include <fmt/color.h>
int main() { print(fg(fmt::color::crimson) | fmt::emphasis::bold, "Hello, {}!\n", "world"); print(fg(fmt::color::floral_white) | bg(fmt::color::slate_gray) | fmt::emphasis::underline, "Hello, {}!\n", "мир"); print(fg(fmt::color::steel_blue) | fmt::emphasis::italic, "Hello, {}!\n", "世界"); }
prints the following on modern terminals with RGB color support:
.. image:: https://user-images.githubusercontent.com/576385/ 50405788-b66e7500-076e-11e9-9592-7324d1f951d8.png
Thanks
@Rakete1111 (Nicolas) <https://github.com/Rakete1111>
_. -
Added support for 4-bit terminal colors (
#968
,#974
).. code:: c++
#include <fmt/color.h>
int main() { print(fg(fmt::terminal_color::red), "stop\n"); }
Note that these colors vary by terminal:
.. image:: https://user-images.githubusercontent.com/576385/ 50405925-dbfc7e00-0770-11e9-9b85-333fab0af9ac.png
Thanks
@Rakete1111 (Nicolas) <https://github.com/Rakete1111>
_. -
Parameterized formatting functions on the type of the format string (
#880
,#881
,#883
,#885
,#897
,#920
). Any object of typeS
that has an overloadedto_string_view(const S&)
returningfmt::string_view
can be used as a format string:.. code:: c++
namespace my_ns { inline string_view to_string_view(const my_string& s) { return {s.data(), s.length()}; } }
std::string message = fmt::format(my_string("The answer is {}."), 42);
Thanks
@DanielaE (Daniela Engert) <https://github.com/DanielaE>
_. -
Made
std::string_view
work as a format string (#898
_):.. code:: c++
auto message = fmt::format(std::string_view("The answer is {}."), 42);
Thanks
@DanielaE (Daniela Engert) <https://github.com/DanielaE>
_. -
Added wide string support to compile-time format string checks (
#924
_):.. code:: c++
print(fmt(L"{:f}"), 42); // compile-time error: invalid type specifier
Thanks
@XZiar <https://github.com/XZiar>
_. -
Made colored print functions work with wide strings (
#867
_):.. code:: c++
#include <fmt/color.h>
int main() { print(fg(fmt::color::red), L"{}\n", 42); }
Thanks
@DanielaE (Daniela Engert) <https://github.com/DanielaE>
_. -
Introduced experimental Unicode support (
#628
,#891
):.. code:: c++
using namespace fmt::literals; auto s = fmt::format("{:*^5}"_u, "🤡"_u); // s == "🤡"_u
-
Improved locale support:
.. code:: c++
#include <fmt/locale.h>
struct numpunct : std::numpunct { protected: char do_thousands_sep() const override { return '~'; } };
std::locale loc; auto s = fmt::format(std::locale(loc, new numpunct()), "{:n}", 1234567); // s == "1~234~567"
-
Constrained formatting functions on proper iterator types (
#921
). Thanks@DanielaE (Daniela Engert) <https://github.com/DanielaE>
. -
Added
make_printf_args
andmake_wprintf_args
functions (#934
). Thanks@tnovotny <https://github.com/tnovotny>
. -
Deprecated
fmt::visit
,parse_context
, andwparse_context
. Usefmt::visit_format_arg
,format_parse_context
, andwformat_parse_context
instead. -
Removed undocumented
basic_fixed_buffer
which has been superseded by the iterator-based API (#873
,#902
). Thanks@superfunc (hollywood programmer) <https://github.com/superfunc>
_. -
Disallowed repeated leading zeros in an argument ID:
.. code:: c++
fmt::print("{000}", 42); // error
-
Reintroduced support for gcc 4.4.
-
Fixed compilation on platforms with exotic
double
(#878
_). -
Improved documentation (
#164
,#877
,#901
,#906
,#979
). Thanks@kookjr (Mathew Cucuzella) <https://github.com/kookjr>
,@DarkDimius (Dmitry Petrashko) <https://github.com/DarkDimius>
,@HecticSerenity <https://github.com/HecticSerenity>
. -
Added pkgconfig support which makes it easier to consume the library from meson and other build systems (
#916
). Thanks@colemickens (Cole Mickens) <https://github.com/colemickens>
. -
Various build improvements (
#909
,#926
,#937
,#953
,#959
). Thanks@tchaikov (Kefu Chai) <https://github.com/tchaikov>
,@luncliff (Park DongHa) <https://github.com/luncliff>
,@AndreasSchoenle (Andreas Schönle) <https://github.com/AndreasSchoenle>
,@hotwatermorning <https://github.com/hotwatermorning>
,@Zefz (JohanJansen) <https://github.com/Zefz>
. -
Improved
string_view
construction performance (#914
). Thanks@gabime (Gabi Melman) <https://github.com/gabime>
. -
Fixed non-matching char types (
#895
). Thanks@DanielaE (Daniela Engert) <https://github.com/DanielaE>
. -
Fixed
format_to_n
withstd::back_insert_iterator
(#913
). Thanks@DanielaE (Daniela Engert) <https://github.com/DanielaE>
. -
Fixed locale-dependent formatting (
#905
_). -
Fixed various compiler warnings and errors (
#882
,#886
,#933
,#941
,#931
,#943
,#954
,#956
,#962
,#965
,#977
,#983
,#989
). Thanks@Luthaf (Guillaume Fraux) <https://github.com/Luthaf>
,@stevenhoving (Steven Hoving) <https://github.com/stevenhoving>
,@christinaa (Kristina Brooks) <https://github.com/christinaa>
,@lgritz (Larry Gritz) <https://github.com/lgritz>
,@DanielaE (Daniela Engert) <https://github.com/DanielaE>
,@0x8000-0000 (Sign Bit) <https://github.com/0x8000-0000>
,@liuping1997 <https://github.com/liuping1997>
.
5.2.1 - 2018-09-21
-
Fixed
visit
lookup issues on gcc 7 & 8 (#870
). Thanks@medithe <https://github.com/medithe>
. -
Fixed linkage errors on older gcc.
-
Prevented
fmt/range.h
from specializingfmt::basic_string_view
(#865
,#868
). Thanks@hhggit (dual) <https://github.com/hhggit>
_. -
Improved error message when formatting unknown types (
#872
). Thanks@foonathan (Jonathan Müller) <https://github.com/foonathan>
, -
Disabled templated user-defined literals when compiled under nvcc (
#875
). Thanks@CandyGumdrop (Candy Gumdrop) <https://github.com/CandyGumdrop>
, -
Fixed
format_to
formatting towmemory_buffer
(#874
_).
5.2.0 - 2018-09-13
-
Optimized format string parsing and argument processing which resulted in up to 5x speed up on long format strings and significant performance boost on various benchmarks. For example, version 5.2 is 2.22x faster than 5.1 on decimal integer formatting with
format_to
(macOS, clang-902.0.39.2):================== ======= ======= Method Time, s Speedup ================== ======= ======= fmt::format 5.1 0.58 fmt::format 5.2 0.35 1.66x fmt::format_to 5.1 0.51 fmt::format_to 5.2 0.23 2.22x sprintf 0.71 std::to_string 1.01 std::stringstream 1.73 ================== ======= =======
-
Changed the
fmt
macro from opt-out to opt-in to prevent name collisions. To enable it define theFMT_STRING_ALIAS
macro to 1 before includingfmt/format.h
:.. code:: c++
#define FMT_STRING_ALIAS 1 #include <fmt/format.h> std::string answer = format(fmt("{}"), 42);
-
Added compile-time format string checks to
format_to
overload that takesfmt::memory_buffer
(#783
_):.. code:: c++
fmt::memory_buffer buf; // Compile-time error: invalid type specifier. fmt::format_to(buf, fmt("{:d}"), "foo");
-
Moved experimental color support to
fmt/color.h
and enabled the new API by default. The old API can be enabled by defining theFMT_DEPRECATED_COLORS
macro. -
Added formatting support for types explicitly convertible to
fmt::string_view
:.. code:: c++
struct foo { explicit operator fmt::string_view() const { return "foo"; } }; auto s = format("{}", foo());
In particular, this makes formatting function work with
folly::StringPiece
. -
Implemented preliminary support for
char*_t
by replacing theformat
function overloads with a single function template parameterized on the string type. -
Added support for dynamic argument lists (
#814
,#819
). Thanks@MikePopoloski (Michael Popoloski) <https://github.com/MikePopoloski>
_. -
Reduced executable size overhead for embedded targets using newlib nano by making locale dependency optional (
#839
). Thanks@teajay-fr (Thomas Benard) <https://github.com/teajay-fr>
. -
Keep
noexcept
specifier when exceptions are disabled (#801
,#810
). Thanks@qis (Alexej Harm) <https://github.com/qis>
_. -
Fixed formatting of user-defined types providing
operator<<
withformat_to_n
(#806
). Thanks@mkurdej (Marek Kurdej) <https://github.com/mkurdej>
. -
Fixed dynamic linkage of new symbols (
#808
_). -
Fixed global initialization issue (
#807
_):.. code:: c++
// This works on compilers with constexpr support. static const std::string answer = fmt::format("{}", 42);
-
Fixed various compiler warnings and errors (
#804
,#809
,#811
,#822
,#827
,#830
,#838
,#843
,#844
,#851
,#852
,#854
). Thanks@henryiii (Henry Schreiner) <https://github.com/henryiii>
,@medithe <https://github.com/medithe>
, and@eliasdaler (Elias Daler) <https://github.com/eliasdaler>
_.
5.1.0 - 2018-07-05
-
Added experimental support for RGB color output enabled with the
FMT_EXTENDED_COLORS
macro:.. code:: c++
#define FMT_EXTENDED_COLORS #define FMT_HEADER_ONLY // or compile fmt with FMT_EXTENDED_COLORS defined #include <fmt/format.h>
fmt::print(fmt::color::steel_blue, "Some beautiful text");
The old API (the
print_colored
andvprint_colored
functions and thecolor
enum) is now deprecated. (#762
_#767
). thanks@Remotion (Remo) <https://github.com/Remotion>
. -
Added quotes to strings in ranges and tuples (
#766
). Thanks@Remotion (Remo) <https://github.com/Remotion>
. -
Made
format_to
work withbasic_memory_buffer
(#776
_). -
Added
vformat_to_n
andwchar_t
overload offormat_to_n
(#764
,#769
). -
Made
is_range
andis_tuple_like
part of public (experimental) API to allow specialization for user-defined types (#751
,#759
). Thanks@drrlvn (Dror Levin) <https://github.com/drrlvn>
_. -
Added more compilers to continuous integration and increased
FMT_PEDANTIC
warning levels (#736
). Thanks@eliaskosunen (Elias Kosunen) <https://github.com/eliaskosunen>
. -
Fixed compilation with MSVC 2013.
-
Fixed handling of user-defined types in
format_to
(#793
_). -
Forced linking of inline
vformat
functions into the library (#795
_). -
Fixed incorrect call to on_align in
'{:}='
(#750
_). -
Fixed floating-point formatting to a non-back_insert_iterator with sign & numeric alignment specified (
#756
_). -
Fixed formatting to an array with
format_to_n
(#778
_). -
Fixed formatting of more than 15 named arguments (
#754
_). -
Fixed handling of compile-time strings when including
fmt/ostream.h
. (#768
_). -
Fixed various compiler warnings and errors (
#742
,#748
,#752
,#770
,#775
,#779
,#780
,#790
,#792
,#800
). Thanks@Remotion (Remo) <https://github.com/Remotion>
,@gabime (Gabi Melman) <https://github.com/gabime>
,@foonathan (Jonathan Müller) <https://github.com/foonathan>
,@Dark-Passenger (Dhruv Paranjape) <https://github.com/Dark-Passenger>
, and@0x8000-0000 (Sign Bit) <https://github.com/0x8000-0000>
_.
5.0.0 - 2018-05-21
-
Added a requirement for partial C++11 support, most importantly variadic templates and type traits, and dropped
FMT_VARIADIC_*
emulation macros. Variadic templates are available since GCC 4.4, Clang 2.9 and MSVC 18.0 (2013). For older compilers use {fmt}version 4.x <https://github.com/fmtlib/fmt/releases/tag/4.1.0>
_ which continues to be maintained and works with C++98 compilers. -
Renamed symbols to follow standard C++ naming conventions and proposed a subset of the library for standardization in
P0645R2 Text Formatting <https://wg21.link/P0645>
_. -
Implemented
constexpr
parsing of format strings andcompile-time format string checks <https://fmt.dev/dev/api.html#compile-time-format-string-checks>
_. For example.. code:: c++
#include <fmt/format.h>
std::string s = format(fmt("{:d}"), "foo");
gives a compile-time error because
d
is an invalid specifier for strings (godbolt <https://godbolt.org/g/rnCy9Q>
__)::... :4:19: note: in instantiation of function template specialization 'fmt::v5::format<S, char [4]>' requested here std::string s = format(fmt("{:d}"), "foo"); ^ format.h:1337:13: note: non-constexpr function 'on_error' cannot be used in a constant expression handler.on_error("invalid type specifier");
Compile-time checks require relaxed
constexpr
(C++14 feature) support. If the latter is not available, checks will be performed at runtime. -
Separated format string parsing and formatting in the extension API to enable compile-time format string processing. For example
.. code:: c++
struct Answer {};
namespace fmt { template <> struct formatter { constexpr auto parse(parse_context& ctx) { auto it = ctx.begin(); spec = *it; if (spec != 'd' && spec != 's') throw format_error("invalid specifier"); return ++it; }
template <typename FormatContext> auto format(Answer, FormatContext& ctx) { return spec == 's' ? format_to(ctx.begin(), "{}", "fourty-two") : format_to(ctx.begin(), "{}", 42); } char spec = 0;
}; }
std::string s = format(fmt("{:x}"), Answer());
gives a compile-time error due to invalid format specifier (
godbolt <https://godbolt.org/g/2jQ1Dv>
__)::... :12:45: error: expression '' is not a constant expression throw format_error("invalid specifier");
-
Added
iterator support <https://fmt.dev/dev/api.html#output-iterator-support>
_:.. code:: c++
#include #include <fmt/format.h>
std::vector out; fmt::format_to(std::back_inserter(out), "{}", 42);
-
Added the
format_to_n <https://fmt.dev/dev/api.html#_CPPv2N3fmt11format_to_nE8OutputItNSt6size_tE11string_viewDpRK4Args>
_ function that restricts the output to the specified number of characters (#298
_):.. code:: c++
char out[4]; fmt::format_to_n(out, sizeof(out), "{}", 12345); // out == "1234" (without terminating '\0')
-
Added the
formatted_size <https://fmt.dev/dev/api.html#_CPPv2N3fmt14formatted_sizeE11string_viewDpRK4Args>
_ function for computing the output size:.. code:: c++
#include <fmt/format.h>
auto size = fmt::formatted_size("{}", 12345); // size == 5
-
Improved compile times by reducing dependencies on standard headers and providing a lightweight
core API <https://fmt.dev/dev/api.html#core-api>
_:.. code:: c++
#include <fmt/core.h>
fmt::print("The answer is {}.", 42);
See
Compile time and code bloat <https://github.com/fmtlib/fmt#compile-time-and-code-bloat>
_. -
Added the
make_format_args <https://fmt.dev/dev/api.html#_CPPv2N3fmt16make_format_argsEDpRK4Args>
_ function for capturing formatting arguments:.. code:: c++
// Prints formatted error message. void vreport_error(const char *format, fmt::format_args args) { fmt::print("Error: "); fmt::vprint(format, args); } template <typename... Args> void report_error(const char *format, const Args & ... args) { vreport_error(format, fmt::make_format_args(args...)); }
-
Added the
make_printf_args
function for capturingprintf
arguments (#687
,#694
). Thanks@Kronuz (Germán Méndez Bravo) <https://github.com/Kronuz>
_. -
Added prefix
v
to non-variadic functions takingformat_args
to distinguish them from variadic ones:.. code:: c++
std::string vformat(string_view format_str, format_args args);
template <typename... Args> std::string format(string_view format_str, const Args & ... args);
-
Added experimental support for formatting ranges, containers and tuple-like types in
fmt/ranges.h
(#735
_):.. code:: c++
#include <fmt/ranges.h>
std::vector v = {1, 2, 3}; fmt::print("{}", v); // prints {1, 2, 3}
Thanks
@Remotion (Remo) <https://github.com/Remotion>
_. -
Implemented
wchar_t
date and time formatting (#712
_):.. code:: c++
#include <fmt/time.h>
std::time_t t = std::time(nullptr); auto s = fmt::format(L"The date is {:%Y-%m-%d}.", *std::localtime(&t));
Thanks
@DanielaE (Daniela Engert) <https://github.com/DanielaE>
_. -
Provided more wide string overloads (
#724
). Thanks@DanielaE (Daniela Engert) <https://github.com/DanielaE>
. -
Switched from a custom null-terminated string view class to
string_view
in the format API and providedfmt::string_view
which implements a subset ofstd::string_view
API for pre-C++17 systems. -
Added support for
std::experimental::string_view
(#607
_):.. code:: c++
#include <fmt/core.h> #include <experimental/string_view>
fmt::print("{}", std::experimental::string_view("foo"));
Thanks
@virgiliofornazin (Virgilio Alexandre Fornazin) <https://github.com/virgiliofornazin>
__. -
Allowed mixing named and automatic arguments:
.. code:: c++
fmt::format("{} {two}", 1, fmt::arg("two", 2));
-
Removed the write API in favor of the
format API <https://fmt.dev/dev/api.html#format-api>
_ with compile-time handling of format strings. -
Disallowed formatting of multibyte strings into a wide character target (
#606
_). -
Improved documentation (
#515
,#614
,#617
,#661
,#680
). Thanks@ibell (Ian Bell) <https://github.com/ibell>
,@mihaitodor (Mihai Todor) <https://github.com/mihaitodor>
, and@johnthagen <https://github.com/johnthagen>
. -
Implemented more efficient handling of large number of format arguments.
-
Introduced an inline namespace for symbol versioning.
-
Added debug postfix
d
to thefmt
library name (#636
_). -
Removed unnecessary
fmt/
prefix in includes (#397
). Thanks@chronoxor (Ivan Shynkarenka) <https://github.com/chronoxor>
. -
Moved
fmt/*.h
toinclude/fmt/*.h
to prevent irrelevant files and directories appearing on the include search paths when fmt is used as a subproject and moved source files to thesrc
directory. -
Added qmake project file
support/fmt.pro
(#641
). Thanks@cowo78 (Giuseppe Corbelli) <https://github.com/cowo78>
. -
Added Gradle build file
support/build.gradle
(#649
). Thanks@luncliff (Park DongHa) <https://github.com/luncliff>
. -
Removed
FMT_CPPFORMAT
CMake option. -
Fixed a name conflict with the macro
CHAR_WIDTH
in glibc (#616
). Thanks@aroig (Abdó Roig-Maranges) <https://github.com/aroig>
. -
Fixed handling of nested braces in
fmt::join
(#638
_). -
Added
SOURCELINK_SUFFIX
for compatibility with Sphinx 1.5 (#497
). Thanks@ginggs (Graham Inggs) <https://github.com/ginggs>
. -
Added a missing
inline
in the header-only mode (#626
). Thanks@aroig (Abdó Roig-Maranges) <https://github.com/aroig>
. -
Fixed various compiler warnings (
#640
,#656
,#679
,#681
,#705
__,#715
,#717
,#720
,#723
,#726
,#730
,#739
). Thanks@peterbell10 <https://github.com/peterbell10>
,@LarsGullik <https://github.com/LarsGullik>
,@foonathan (Jonathan Müller) <https://github.com/foonathan>
,@eliaskosunen (Elias Kosunen) <https://github.com/eliaskosunen>
,@christianparpart (Christian Parpart) <https://github.com/christianparpart>
,@DanielaE (Daniela Engert) <https://github.com/DanielaE>
, and@mwinterb <https://github.com/mwinterb>
. -
Worked around an MSVC bug and fixed several warnings (
#653
). Thanks@alabuzhev (Alex Alabuzhev) <https://github.com/alabuzhev>
. -
Worked around GCC bug 67371 (
#682
_). -
Fixed compilation with
-fno-exceptions
(#655
). Thanks@chenxiaolong (Andrew Gunnerson) <https://github.com/chenxiaolong>
. -
Made
constexpr remove_prefix
gcc version check tighter (#648
_). -
Renamed internal type enum constants to prevent collision with poorly written C libraries (
#644
_). -
Added detection of
wostream operator<<
(#650
_). -
Fixed compilation on OpenBSD (
#660
). Thanks@hubslave <https://github.com/hubslave>
. -
Fixed compilation on FreeBSD 12 (
#732
). Thanks@dankm <https://github.com/dankm>
. -
Fixed compilation when there is a mismatch between
-std
options between the library and user code (#664
_). -
Fixed compilation with GCC 7 and
-std=c++11
(#734
_). -
Improved generated binary code on GCC 7 and older (
#668
_). -
Fixed handling of numeric alignment with no width (
#675
_). -
Fixed handling of empty strings in UTF8/16 converters (
#676
). Thanks@vgalka-sl (Vasili Galka) <https://github.com/vgalka-sl>
. -
Fixed formatting of an empty
string_view
(#689
_). -
Fixed detection of
string_view
on libc++ (#686
_). -
Fixed DLL issues (
#696
). Thanks@sebkoenig <https://github.com/sebkoenig>
. -
Fixed compile checks for mixing narrow and wide strings (
#690
_). -
Disabled unsafe implicit conversion to
std::string
(#729
_). -
Fixed handling of reused format specs (as in
fmt::join
) for pointers (#725
). Thanks@mwinterb <https://github.com/mwinterb>
. -
Fixed installation of
fmt/ranges.h
(#738
). Thanks@sv1990 <https://github.com/sv1990>
.
4.1.0 - 2017-12-20
-
Added
fmt::to_wstring()
in addition tofmt::to_string()
(#559
). Thanks@alabuzhev (Alex Alabuzhev) <https://github.com/alabuzhev>
. -
Added support for C++17
std::string_view
(#571
_ and#578
). Thanks@thelostt (Mário Feroldi) <https://github.com/thelostt>
and@mwinterb <https://github.com/mwinterb>
_. -
Enabled stream exceptions to catch errors (
#581
). Thanks@crusader-mike <https://github.com/crusader-mike>
. -
Allowed formatting of class hierarchies with
fmt::format_arg()
(#547
). Thanks@rollbear (Björn Fahller) <https://github.com/rollbear>
. -
Removed limitations on character types (
#563
). Thanks@Yelnats321 (Elnar Dakeshov) <https://github.com/Yelnats321>
. -
Conditionally enabled use of
std::allocator_traits
(#583
). Thanks@mwinterb <https://github.com/mwinterb>
. -
Added support for
const
variadic member function emulation withFMT_VARIADIC_CONST
(#591
). Thanks@ludekvodicka (Ludek Vodicka) <https://github.com/ludekvodicka>
. -
Various bugfixes: bad overflow check, unsupported implicit type conversion when determining formatting function, test segfaults (
#551
), ill-formed macros (#542
) and ambiguous overloads (#580
). Thanks@xylosper (Byoung-young Lee) <https://github.com/xylosper>
. -
Prevented warnings on MSVC (
#605
,#602
, and#545
), clang (#582
), GCC (#573
), various conversion warnings (#609
,#567
,#553
and#553
), and addedoverride
and[[noreturn]]
(#549
and#555
). Thanks@alabuzhev (Alex Alabuzhev) <https://github.com/alabuzhev>
,@virgiliofornazin (Virgilio Alexandre Fornazin) <https://gihtub.com/virgiliofornazin>
,@alexanderbock (Alexander Bock) <https://github.com/alexanderbock>
,@yumetodo <https://github.com/yumetodo>
,@VaderY (Császár Mátyás) <https://github.com/VaderY>
,@jpcima (JP Cimalando) <https://github.com/jpcima>
,@thelostt (Mário Feroldi) <https://github.com/thelostt>
, and@Manu343726 (Manu Sánchez) <https://github.com/Manu343726>
_. -
Improved CMake: Used
GNUInstallDirs
to set installation location (#610
) and fixed warnings (#536
and#556
). Thanks@mikecrowe (Mike Crowe) <https://github.com/mikecrowe>
,@evgen231 <https://github.com/evgen231>
_ and@henryiii (Henry Schreiner) <https://github.com/henryiii>
_.
4.0.0 - 2017-06-27
-
Removed old compatibility headers
cppformat/*.h
and CMake options (#527
). Thanks@maddinat0r (Alex Martin) <https://github.com/maddinat0r>
. -
Added
string.h
containingfmt::to_string()
as alternative tostd::to_string()
as well as other string writer functionality (#326
_ and#441
_):.. code:: c++
#include "fmt/string.h"
std::string answer = fmt::to_string(42);
Thanks to
@glebov-andrey (Andrey Glebov) <https://github.com/glebov-andrey>
_. -
Moved
fmt::printf()
to newprintf.h
header and allowed%s
as generic specifier (#453
), made%.f
more conformant to regularprintf()
(#490
), added custom writer support (#476
) and implemented missing custom argument formatting (#339
and#340
_):.. code:: c++
#include "fmt/printf.h"
// %s format specifier can be used with any argument type. fmt::printf("%s", 42);
Thanks
@mojoBrendan <https://github.com/mojoBrendan>
,@manylegged (Arthur Danskin) <https://github.com/manylegged>
and@spacemoose (Glen Stark) <https://github.com/spacemoose>
. See also#360
,#335
_ and#331
_. -
Added
container.h
containing aBasicContainerWriter
to write to containers likestd::vector
(#450
). Thanks@polyvertex (Jean-Charles Lefebvre) <https://github.com/polyvertex>
. -
Added
fmt::join()
function that takes a range and formats its elements separated by a given string (#466
_):.. code:: c++
#include "fmt/format.h"
std::vector v = {1.2, 3.4, 5.6}; // Prints "(+01.20, +03.40, +05.60)". fmt::print("({:+06.2f})", fmt::join(v.begin(), v.end(), ", "));
Thanks
@olivier80 <https://github.com/olivier80>
_. -
Added support for custom formatting specifications to simplify customization of built-in formatting (
#444
). Thanks@polyvertex (Jean-Charles Lefebvre) <https://github.com/polyvertex>
. See also#439
_. -
Added
fmt::format_system_error()
for error code formatting (#323
_ and#526
). Thanks@maddinat0r (Alex Martin) <https://github.com/maddinat0r>
. -
Added thread-safe
fmt::localtime()
andfmt::gmtime()
as replacement for the standard version totime.h
(#396
). Thanks@codicodi <https://github.com/codicodi>
. -
Internal improvements to
NamedArg
andArgLists
(#389
_ and#390
). Thanks@chronoxor <https://github.com/chronoxor>
. -
Fixed crash due to bug in
FormatBuf
(#493
). Thanks@effzeh <https://github.com/effzeh>
. See also#480
_ and#491
_. -
Fixed handling of wide strings in
fmt::StringWriter
. -
Improved compiler error messages (
#357
_). -
Fixed various warnings and issues with various compilers (
#494
,#499
,#483
,#485
,#482
,#475
,#473
_ and#414
). Thanks@chronoxor <https://github.com/chronoxor>
,@zhaohuaxishi <https://github.com/zhaohuaxishi>
,@pkestene (Pierre Kestener) <https://github.com/pkestene>
,@dschmidt (Dominik Schmidt) <https://github.com/dschmidt>
_ and@0x414c (Alexey Gorishny) <https://github.com/0x414c>
_ . -
Improved CMake: targets are now namespaced (
#511
_ and#513
), added support for header-onlyprintf.h
(#354
), fixed issue with minimal supported library subset (#418
,#419
and#420
). Thanks@bjoernthiel (Bjoern Thiel) <https://github.com/bjoernthiel>
,@niosHD (Mario Werner) <https://github.com/niosHD>
,@LogicalKnight (Sean LK) <https://github.com/LogicalKnight>
and@alabuzhev (Alex Alabuzhev) <https://github.com/alabuzhev>
_. -
Improved documentation. Thanks to
@pwm1234 (Phil) <https://github.com/pwm1234>
_ for#393
_.
3.0.2 - 2017-06-14
-
Added
FMT_VERSION
macro (#411
_). -
Used
FMT_NULL
instead of literal0
(#409
). Thanks@alabuzhev (Alex Alabuzhev) <https://github.com/alabuzhev>
. -
Added extern templates for
format_float
(#413
_). -
Fixed implicit conversion issue (
#507
_). -
Fixed signbit detection (
#423
_). -
Fixed naming collision (
#425
_). -
Fixed missing intrinsic for C++/CLI (
#457
). Thanks@calumr (Calum Robinson) <https://github.com/calumr>
-
Fixed Android detection (
#458
). Thanks@Gachapen (Magnus Bjerke Vik) <https://github.com/Gachapen>
. -
Use lean
windows.h
if not in header-only mode (#503
). Thanks@Quentin01 (Quentin Buathier) <https://github.com/Quentin01>
. -
Fixed issue with CMake exporting C++11 flag (
#445
). Thanks@EricWF (Eric) <https://github.com/EricWF>
. -
Fixed issue with nvcc and MSVC compiler bug and MinGW (
#505
_). -
Fixed DLL issues (
#469
_ and#502
). Thanks@richardeakin (Richard Eakin) <https://github.com/richardeakin>
and@AndreasSchoenle (Andreas Schönle) <https://github.com/AndreasSchoenle>
_. -
Fixed test compilation under FreeBSD (
#433
_). -
Fixed various warnings (
#403
,#410
and#510
). Thanks@Lecetem <https://github.com/Lectem>
,@chenhayat (Chen Hayat) <https://github.com/chenhayat>
_ and@trozen <https://github.com/trozen>
_. -
Worked around a broken
__builtin_clz
in clang with MS codegen (#519
_). -
Removed redundant include (
#479
_). -
Fixed documentation issues.
3.0.1 - 2016-11-01
-
Fixed handling of thousands separator (
#353
_). -
Fixed handling of
unsigned char
strings (#373
_). -
Corrected buffer growth when formatting time (
#367
_). -
Removed warnings under MSVC and clang (
#318
,#250
, also merged#385
_ and#361
). Thanks@jcelerier (Jean-Michaël Celerier) <https://github.com/jcelerier>
and@nmoehrle (Nils Moehrle) <https://github.com/nmoehrle>
_. -
Fixed compilation issues under Android (
#327
,#345
and#381
), FreeBSD (#358
), Cygwin (#388
), MinGW (#355
) as well as other issues (#350
,#366
,#348
,#402
,#405
). Thanks to@dpantele (Dmitry) <https://github.com/dpantele>
,@hghwng (Hugh Wang) <https://github.com/hghwng>
,@arvedarved (Tilman Keskinöz) <https://github.com/arvedarved>
,@LogicalKnight (Sean) <https://github.com/LogicalKnight>
_ and@JanHellwig (Jan Hellwig) <https://github.com/janhellwig>
_. -
Fixed some documentation issues and extended specification (
#320
,#333
,#347
,#362
). Thanks to@smellman (Taro Matsuzawa aka. btm) <https://github.com/smellman>
_.
3.0.0 - 2016-05-07
-
The project has been renamed from C++ Format (cppformat) to fmt for consistency with the used namespace and macro prefix (
#307
_). Library headers are now located in thefmt
directory:.. code:: c++
#include "fmt/format.h"
Including
format.h
from thecppformat
directory is deprecated but works via a proxy header which will be removed in the next major version.The documentation is now available at https://fmt.dev.
-
Added support for
strftime <http://en.cppreference.com/w/cpp/chrono/c/strftime>
-likedate and time formatting <https://fmt.dev/3.0.0/api.html#date-and-time-formatting>
(#283
_):.. code:: c++
#include "fmt/time.h"
std::time_t t = std::time(nullptr); // Prints "The date is 2016-04-29." (with the current date) fmt::print("The date is {:%Y-%m-%d}.", *std::localtime(&t));
-
std::ostream
support including formatting of user-defined types that provide overloadedoperator<<
has been moved tofmt/ostream.h
:.. code:: c++
#include "fmt/ostream.h"
class Date { int year_, month_, day_; public: Date(int year, int month, int day) : year_(year), month_(month), day_(day) {}
friend std::ostream &operator<<(std::ostream &os, const Date &d) { return os << d.year_ << '-' << d.month_ << '-' << d.day_; }
};
std::string s = fmt::format("The date is {}", Date(2012, 12, 9)); // s == "The date is 2012-12-9"
-
Added support for
custom argument formatters <https://fmt.dev/3.0.0/api.html#argument-formatters>
_ (#235
_). -
Added support for locale-specific integer formatting with the
n
specifier (#305
_):.. code:: c++
std::setlocale(LC_ALL, "en_US.utf8"); fmt::print("cppformat: {:n}\n", 1234567); // prints 1,234,567
-
Sign is now preserved when formatting an integer with an incorrect
printf
format specifier (#265
_):.. code:: c++
fmt::printf("%lld", -42); // prints -42
Note that it would be an undefined behavior in
std::printf
. -
Length modifiers such as
ll
are now optional in printf formatting functions and the correct type is determined automatically (#255
_):.. code:: c++
fmt::printf("%d", std::numeric_limits::max());
Note that it would be an undefined behavior in
std::printf
. -
Added initial support for custom formatters (
#231
_). -
Fixed detection of user-defined literal support on Intel C++ compiler (
#311
,#312
). Thanks to@dean0x7d (Dean Moldovan) <https://github.com/dean0x7d>
_ and@speth (Ray Speth) <https://github.com/speth>
_. -
Reduced compile time (
#243
,#249
,#317
_):.. image:: https://cloud.githubusercontent.com/assets/4831417/11614060/ b9e826d2-9c36-11e5-8666-d4131bf503ef.png
.. image:: https://cloud.githubusercontent.com/assets/4831417/11614080/ 6ac903cc-9c37-11e5-8165-26df6efae364.png
Thanks to
@dean0x7d (Dean Moldovan) <https://github.com/dean0x7d>
_. -
Compile test fixes (
#313
). Thanks to@dean0x7d (Dean Moldovan) <https://github.com/dean0x7d>
. -
Documentation fixes (
#239
,#248
,#252
,#258
,#260
,#301
,#309
). Thanks to@ReadmeCritic <https://github.com/ReadmeCritic>
@Gachapen (Magnus Bjerke Vik) <https://github.com/Gachapen>
_ and@jwilk (Jakub Wilk) <https://github.com/jwilk>
_. -
Fixed compiler and sanitizer warnings (
#244
,#256
,#259
,#263
,#274
,#277
,#286
,#291
,#296
,#308
) Thanks to@mwinterb <https://github.com/mwinterb>
,@pweiskircher (Patrik Weiskircher) <https://github.com/pweiskircher>
,@Naios <https://github.com/Naios>
_. -
Improved compatibility with Windows Store apps (
#280
,#285
). Thanks to@mwinterb <https://github.com/mwinterb>
_. -
Added tests of compatibility with older C++ standards (
#273
). Thanks to@niosHD <https://github.com/niosHD>
. -
Fixed Android build (
#271
). Thanks to@newnon <https://github.com/newnon>
. -
Changed
ArgMap
to be backed by a vector instead of a map. (#261
,#262
). Thanks to@mwinterb <https://github.com/mwinterb>
_. -
Added
fprintf
overload that writes to astd::ostream
(#251
). Thanks tonickhutchinson (Nicholas Hutchinson) <https://github.com/nickhutchinson>
. -
Export symbols when building a Windows DLL (
#245
). Thanks tomacdems (Maciek Dems) <https://github.com/macdems>
. -
Fixed compilation on Cygwin (
#304
_). -
Implemented a workaround for a bug in Apple LLVM version 4.2 of clang (
#276
_). -
Implemented a workaround for Google Test bug
#705 <https://github.com/google/googletest/issues/705>
_ on gcc 6 (#268
). Thanks tooctoploid <https://github.com/octoploid>
. -
Removed Biicode support because the latter has been discontinued.
2.1.1 - 2016-04-11
-
The install location for generated CMake files is now configurable via the
FMT_CMAKE_DIR
CMake variable (#299
). Thanks to@niosHD <https://github.com/niosHD>
. -
Documentation fixes (
#252
_).
2.1.0 - 2016-03-21
-
Project layout and build system improvements (
#267
_):-
The code have been moved to the
cppformat
directory. Includingformat.h
from the top-level directory is deprecated but works via a proxy header which will be removed in the next major version. -
C++ Format CMake targets now have proper interface definitions.
-
Installed version of the library now supports the header-only configuration.
-
Targets
doc
,install
, andtest
are now disabled if C++ Format is included as a CMake subproject. They can be enabled by settingFMT_DOC
,FMT_INSTALL
, andFMT_TEST
in the parent project.
Thanks to
@niosHD <https://github.com/niosHD>
_. -
2.0.1 - 2016-03-13
-
Improved CMake find and package support (
#264
). Thanks to@niosHD <https://github.com/niosHD>
. -
Fix compile error with Android NDK and mingw32 (
#241
). Thanks to@Gachapen (Magnus Bjerke Vik) <https://github.com/Gachapen>
. -
Documentation fixes (
#248
,#260
).
2.0.0 - 2015-12-01
General
* [Breaking] Named arguments (`#169`_, `#173`_, `#174`_):
.. code:: c++
fmt::print("The answer is {answer}.", fmt::arg("answer", 42));
Thanks to `@jamboree <https://github.com/jamboree>`_.
* [Experimental] User-defined literals for format and named arguments
(`#204`_, `#206`_, `#207`_):
.. code:: c++
using namespace fmt::literals;
fmt::print("The answer is {answer}.", "answer"_a=42);
Thanks to `@dean0x7d (Dean Moldovan) <https://github.com/dean0x7d>`_.
* [Breaking] Formatting of more than 16 arguments is now supported when using
variadic templates (`#141`_).
Thanks to `@Shauren <https://github.com/Shauren>`_.
* Runtime width specification (`#168`_):
.. code:: c++
fmt::format("{0:{1}}", 42, 5); // gives " 42"
Thanks to `@jamboree <https://github.com/jamboree>`_.
* [Breaking] Enums are now formatted with an overloaded ``std::ostream``
insertion operator (``operator<<``) if available (`#232`_).
* [Breaking] Changed default ``bool`` format to textual, "true" or "false"
(`#170`_):
.. code:: c++
fmt::print("{}", true); // prints "true"
To print ``bool`` as a number use numeric format specifier such as ``d``:
.. code:: c++
fmt::print("{:d}", true); // prints "1"
* ``fmt::printf`` and ``fmt::sprintf`` now support formatting of ``bool`` with
the ``%s`` specifier giving textual output, "true" or "false" (`#223`_):
.. code:: c++
fmt::printf("%s", true); // prints "true"
Thanks to `@LarsGullik <https://github.com/LarsGullik>`_.
* [Breaking] ``signed char`` and ``unsigned char`` are now formatted as integers
by default (`#217`_).
* [Breaking] Pointers to C strings can now be formatted with the ``p`` specifier
(`#223`_):
.. code:: c++
fmt::print("{:p}", "test"); // prints pointer value
Thanks to `@LarsGullik <https://github.com/LarsGullik>`_.
* [Breaking] ``fmt::printf`` and ``fmt::sprintf`` now print null pointers as
``(nil)`` and null strings as ``(null)`` for consistency with glibc (`#226`_).
Thanks to `@LarsGullik <https://github.com/LarsGullik>`_.
* [Breaking] ``fmt::(s)printf`` now supports formatting of objects of
user-defined types that provide an overloaded ``std::ostream`` insertion
operator (``operator<<``) (`#201`_):
.. code:: c++
fmt::printf("The date is %s", Date(2012, 12, 9));
* [Breaking] The ``Buffer`` template is now part of the public API and can be
used to implement custom memory buffers (`#140`_). Thanks to
`@polyvertex (Jean-Charles Lefebvre) <https://github.com/polyvertex>`_.
* [Breaking] Improved compatibility between ``BasicStringRef`` and
`std::experimental::basic_string_view
<http://en.cppreference.com/w/cpp/experimental/basic_string_view>`_
(`#100`_, `#159`_, `#183`_):
- Comparison operators now compare string content, not pointers
- ``BasicStringRef::c_str`` replaced by ``BasicStringRef::data``
- ``BasicStringRef`` is no longer assumed to be null-terminated
References to null-terminated strings are now represented by a new class,
``BasicCStringRef``.
* Dependency on pthreads introduced by Google Test is now optional (`#185`_).
* New CMake options ``FMT_DOC``, ``FMT_INSTALL`` and ``FMT_TEST`` to control
generation of ``doc``, ``install`` and ``test`` targets respectively, on by
default (`#197`_, `#198`_, `#200`_).
Thanks to `@maddinat0r (Alex Martin) <https://github.com/maddinat0r>`_.
* ``noexcept`` is now used when compiling with MSVC2015 (`#215`_).
Thanks to `@dmkrepo (Dmitriy) <https://github.com/dmkrepo>`_.
* Added an option to disable use of ``windows.h`` when ``FMT_USE_WINDOWS_H``
is defined as 0 before including ``format.h`` (`#171`_).
Thanks to `@alfps (Alf P. Steinbach) <https://github.com/alfps>`_.
* [Breaking] ``windows.h`` is now included with ``NOMINMAX`` unless
``FMT_WIN_MINMAX`` is defined. This is done to prevent breaking code using
``std::min`` and ``std::max`` and only affects the header-only configuration
(`#152`_, `#153`_, `#154`_).
Thanks to `@DevO2012 <https://github.com/DevO2012>`_.
* Improved support for custom character types (`#171`_).
Thanks to `@alfps (Alf P. Steinbach) <https://github.com/alfps>`_.
* Added an option to disable use of IOStreams when ``FMT_USE_IOSTREAMS``
is defined as 0 before including ``format.h`` (`#205`_, `#208`_).
Thanks to `@JodiTheTigger <https://github.com/JodiTheTigger>`_.
* Improved detection of ``isnan``, ``isinf`` and ``signbit``.
Optimization
-
Made formatting of user-defined types more efficient with a custom stream buffer (
#92
,#230
). Thanks to@NotImplemented <https://github.com/NotImplemented>
_. -
Further improved performance of
fmt::Writer
on integer formatting and fixed a minor regression. Now it is ~7% faster thankarma::generate
on Karma's benchmark (#186
_). -
[Breaking] Reduced
compiled code size <https://github.com/fmtlib/fmt#compile-time-and-code-bloat>
_ (#143
,#149
).
Distribution
* [Breaking] Headers are now installed in
``${CMAKE_INSTALL_PREFIX}/include/cppformat`` (`#178`_).
Thanks to `@jackyf (Eugene V. Lyubimkin) <https://github.com/jackyf>`_.
* [Breaking] Changed the library name from ``format`` to ``cppformat``
for consistency with the project name and to avoid potential conflicts
(`#178`_).
Thanks to `@jackyf (Eugene V. Lyubimkin) <https://github.com/jackyf>`_.
* C++ Format is now available in `Debian <https://www.debian.org/>`_ GNU/Linux
(`stretch <https://packages.debian.org/source/stretch/cppformat>`_,
`sid <https://packages.debian.org/source/sid/cppformat>`_) and
derived distributions such as
`Ubuntu <https://launchpad.net/ubuntu/+source/cppformat>`_ 15.10 and later
(`#155`_)::
$ sudo apt-get install libcppformat1-dev
Thanks to `@jackyf (Eugene V. Lyubimkin) <https://github.com/jackyf>`_.
* `Packages for Fedora and RHEL
<https://admin.fedoraproject.org/pkgdb/package/cppformat/>`_ are now
available. Thanks to Dave Johansen.
* C++ Format can now be installed via `Homebrew <http://brew.sh/>`_ on OS X
(`#157`_)::
$ brew install cppformat
Thanks to `@ortho <https://github.com/ortho>`_, Anatoliy Bulukin.
Documentation
-
Migrated from ReadTheDocs to GitHub Pages for better responsiveness and reliability (
#128
_). New documentation address is http://cppformat.github.io/. -
Added
Building the documentation <https://fmt.dev/2.0.0/usage.html#building-the-documentation>
_ section to the documentation. -
Documentation build script is now compatible with Python 3 and newer pip versions (
#189
,#209
). Thanks to@JodiTheTigger <https://github.com/JodiTheTigger>
_ and@xentec <https://github.com/xentec>
_. -
Documentation fixes and improvements (
#36
,#75
,#125
,#160
,#161
,#162
,#165
,#210
). Thanks to@syohex (Syohei YOSHIDA) <https://github.com/syohex>
_ and bug reporters. -
Fixed out-of-tree documentation build (
#177
). Thanks to@jackyf (Eugene V. Lyubimkin) <https://github.com/jackyf>
.
Fixes
* Fixed ``initializer_list`` detection (`#136`_).
Thanks to `@Gachapen (Magnus Bjerke Vik) <https://github.com/Gachapen>`_.
* [Breaking] Fixed formatting of enums with numeric format specifiers in
``fmt::(s)printf`` (`#131`_, `#139`_):
.. code:: c++
enum { ANSWER = 42 };
fmt::printf("%d", ANSWER);
Thanks to `@Naios <https://github.com/Naios>`_.
* Improved compatibility with old versions of MinGW
(`#129`_, `#130`_, `#132`_).
Thanks to `@cstamford (Christopher Stamford) <https://github.com/cstamford>`_.
* Fixed a compile error on MSVC with disabled exceptions (`#144`_).
* Added a workaround for broken implementation of variadic templates in MSVC2012
(`#148`_).
* Placed the anonymous namespace within ``fmt`` namespace for the header-only
configuration (`#171`_).
Thanks to `@alfps (Alf P. Steinbach) <https://github.com/alfps>`_.
* Fixed issues reported by Coverity Scan (`#187`_, `#192`_).
* Implemented a workaround for a name lookup bug in MSVC2010 (`#188`_).
* Fixed compiler warnings (`#95`_, `#96`_, `#114`_, `#135`_, `#142`_, `#145`_,
`#146`_, `#158`_, `#163`_, `#175`_, `#190`_, `#191`_, `#194`_, `#196`_,
`#216`_, `#218`_, `#220`_, `#229`_, `#233`_, `#234`_, `#236`_, `#281`_,
`#289`_). Thanks to
`@seanmiddleditch (Sean Middleditch) <https://github.com/seanmiddleditch>`_,
`@dixlorenz (Dix Lorenz) <https://github.com/dixlorenz>`_,
`@CarterLi (李通洲) <https://github.com/CarterLi>`_,
`@Naios <https://github.com/Naios>`_,
`@fmatthew5876 (Matthew Fioravante) <https://github.com/fmatthew5876>`_,
`@LevskiWeng (Levski Weng) <https://github.com/LevskiWeng>`_,
`@rpopescu <https://github.com/rpopescu>`_,
`@gabime (Gabi Melman) <https://github.com/gabime>`_,
`@cubicool (Jeremy Moles) <https://github.com/cubicool>`_,
`@jkflying (Julian Kent) <https://github.com/jkflying>`_,
`@LogicalKnight (Sean L) <https://github.com/LogicalKnight>`_,
`@inguin (Ingo van Lil) <https://github.com/inguin>`_ and
`@Jopie64 (Johan) <https://github.com/Jopie64>`_.
* Fixed portability issues (mostly causing test failures) on ARM, ppc64,
ppc64le, s390x and SunOS 5.11 i386 (`#138`_, `#179`_, `#180`_, `#202`_,
`#225`_, `Red Hat Bugzilla Bug 1260297
<https://bugzilla.redhat.com/show_bug.cgi?id=1260297>`_).
Thanks to `@Naios <https://github.com/Naios>`_,
`@jackyf (Eugene V. Lyubimkin) <https://github.com/jackyf>`_ and
Dave Johansen.
* Fixed a name conflict with macro ``free`` defined in ``crtdbg.h`` when
``_CRTDBG_MAP_ALLOC`` is set (`#211`_).
* Fixed shared library build on OS X (`#212`_).
Thanks to `@dean0x7d (Dean Moldovan) <https://github.com/dean0x7d>`_.
* Fixed an overload conflict on MSVC when ``/Zc:wchar_t-`` option is specified
(`#214`_).
Thanks to `@slavanap (Vyacheslav Napadovsky) <https://github.com/slavanap>`_.
* Improved compatibility with MSVC 2008 (`#236`_).
Thanks to `@Jopie64 (Johan) <https://github.com/Jopie64>`_.
* Improved compatibility with bcc32 (`#227`_).
* Fixed ``static_assert`` detection on Clang (`#228`_).
Thanks to `@dean0x7d (Dean Moldovan) <https://github.com/dean0x7d>`_.
1.1.0 - 2015-03-06
------------------
* Added ``BasicArrayWriter``, a class template that provides operations for
formatting and writing data into a fixed-size array
(`#105`_ and `#122`_):
.. code:: c++
char buffer[100];
fmt::ArrayWriter w(buffer);
w.write("The answer is {}", 42);
* Added `0 A.D. <http://play0ad.com/>`_ and `PenUltima Online (POL)
<http://www.polserver.com/>`_ to the list of notable projects using C++ Format.
* C++ Format now uses MSVC intrinsics for better formatting performance
(`#115`_, `#116`_, `#118`_ and `#121`_).
Previously these optimizations where only used on GCC and Clang.
Thanks to `@CarterLi <https://github.com/CarterLi>`_ and
`@objectx <https://github.com/objectx>`_.
* CMake install target (`#119`_).
Thanks to `@TrentHouliston <https://github.com/TrentHouliston>`_.
You can now install C++ Format with ``make install`` command.
* Improved `Biicode <http://www.biicode.com/>`_ support
(`#98`_ and `#104`_). Thanks to
`@MariadeAnton <https://github.com/MariadeAnton>`_ and
`@franramirez688 <https://github.com/franramirez688>`_.
* Improved support for building with `Android NDK
<https://developer.android.com/tools/sdk/ndk/index.html>`_ (`#107`_).
Thanks to `@newnon <https://github.com/newnon>`_.
The `android-ndk-example <https://github.com/fmtlib/android-ndk-example>`_
repository provides and example of using C++ Format with Android NDK:
.. image:: https://raw.githubusercontent.com/fmtlib/android-ndk-example/
master/screenshot.png
* Improved documentation of ``SystemError`` and ``WindowsError`` (`#54`_).
* Various code improvements (`#110`_, `#111`_ `#112`_).
Thanks to `@CarterLi <https://github.com/CarterLi>`_.
* Improved compile-time errors when formatting wide into narrow strings
(`#117`_).
* Fixed ``BasicWriter::write`` without formatting arguments when C++11 support
is disabled (`#109`_).
* Fixed header-only build on OS X with GCC 4.9 (`#124`_).
* Fixed packaging issues (`#94`_).
* Added `changelog <https://github.com/fmtlib/fmt/blob/master/ChangeLog.rst>`_
(`#103`_).
1.0.0 - 2015-02-05
------------------
* Add support for a header-only configuration when ``FMT_HEADER_ONLY`` is
defined before including ``format.h``:
.. code:: c++
#define FMT_HEADER_ONLY
#include "format.h"
* Compute string length in the constructor of ``BasicStringRef``
instead of the ``size`` method
(`#79`_).
This eliminates size computation for string literals on reasonable optimizing
compilers.
* Fix formatting of types with overloaded ``operator <<`` for ``std::wostream``
(`#86`_):
.. code:: c++
fmt::format(L"The date is {0}", Date(2012, 12, 9));
* Fix linkage of tests on Arch Linux (`#89`_).
* Allow precision specifier for non-float arguments (`#90`_):
.. code:: c++
fmt::print("{:.3}\n", "Carpet"); // prints "Car"
* Fix build on Android NDK (`#93`_)
* Improvements to documentation build procedure.
* Remove ``FMT_SHARED`` CMake variable in favor of standard `BUILD_SHARED_LIBS
<http://www.cmake.org/cmake/help/v3.0/variable/BUILD_SHARED_LIBS.html>`_.
* Fix error handling in ``fmt::fprintf``.
* Fix a number of warnings.
0.12.0 - 2014-10-25
-------------------
* [Breaking] Improved separation between formatting and buffer management.
``Writer`` is now a base class that cannot be instantiated directly.
The new ``MemoryWriter`` class implements the default buffer management
with small allocations done on stack. So ``fmt::Writer`` should be replaced
with ``fmt::MemoryWriter`` in variable declarations.
Old code:
.. code:: c++
fmt::Writer w;
New code:
.. code:: c++
fmt::MemoryWriter w;
If you pass ``fmt::Writer`` by reference, you can continue to do so:
.. code:: c++
void f(fmt::Writer &w);
This doesn't affect the formatting API.
* Support for custom memory allocators (`#69`_)
* Formatting functions now accept `signed char` and `unsigned char` strings as
arguments (`#73`_):
.. code:: c++
auto s = format("GLSL version: {}", glGetString(GL_VERSION));
* Reduced code bloat. According to the new `benchmark results
<https://github.com/fmtlib/fmt#compile-time-and-code-bloat>`_,
cppformat is close to ``printf`` and by the order of magnitude better than
Boost Format in terms of compiled code size.
* Improved appearance of the documentation on mobile by using the `Sphinx
Bootstrap theme <http://ryan-roemer.github.io/sphinx-bootstrap-theme/>`_:
.. |old| image:: https://cloud.githubusercontent.com/assets/576385/4792130/
cd256436-5de3-11e4-9a62-c077d0c2b003.png
.. |new| image:: https://cloud.githubusercontent.com/assets/576385/4792131/
cd29896c-5de3-11e4-8f59-cac952942bf0.png
+-------+-------+
| Old | New |
+-------+-------+
| |old| | |new| |
+-------+-------+
0.11.0 - 2014-08-21
-------------------
* Safe printf implementation with a POSIX extension for positional arguments:
.. code:: c++
fmt::printf("Elapsed time: %.2f seconds", 1.23);
fmt::printf("%1$s, %3$d %2$s", weekday, month, day);
* Arguments of ``char`` type can now be formatted as integers (`#55`_):
.. code:: c++
fmt::format("0x{0:02X}", 'a');
* Deprecated parts of the API removed.
* The library is now built and tested on MinGW with Appveyor in addition to
existing test platforms Linux/GCC, OS X/Clang, Windows/MSVC.
0.10.0 - 2014-07-01
-------------------
**Improved API**
* All formatting methods are now implemented as variadic functions instead
of using ``operator<<`` for feeding arbitrary arguments into a temporary
formatter object. This works both with C++11 where variadic templates are
used and with older standards where variadic functions are emulated by
providing lightweight wrapper functions defined with the ``FMT_VARIADIC``
macro. You can use this macro for defining your own portable variadic
functions:
.. code:: c++
void report_error(const char *format, const fmt::ArgList &args) {
fmt::print("Error: {}");
fmt::print(format, args);
}
FMT_VARIADIC(void, report_error, const char *)
report_error("file not found: {}", path);
Apart from a more natural syntax, this also improves performance as there
is no need to construct temporary formatter objects and control arguments'
lifetimes. Because the wrapper functions are very lightweight, this doesn't
cause code bloat even in pre-C++11 mode.
* Simplified common case of formatting an ``std::string``. Now it requires a
single function call:
.. code:: c++
std::string s = format("The answer is {}.", 42);
Previously it required 2 function calls:
.. code:: c++
std::string s = str(Format("The answer is {}.") << 42);
Instead of unsafe ``c_str`` function, ``fmt::Writer`` should be used directly
to bypass creation of ``std::string``:
.. code:: c++
fmt::Writer w;
w.write("The answer is {}.", 42);
w.c_str(); // returns a C string
This doesn't do dynamic memory allocation for small strings and is less error
prone as the lifetime of the string is the same as for ``std::string::c_str``
which is well understood (hopefully).
* Improved consistency in naming functions that are a part of the public API.
Now all public functions are lowercase following the standard library
conventions. Previously it was a combination of lowercase and
CapitalizedWords.
Issue `#50`_.
* Old functions are marked as deprecated and will be removed in the next
release.
**Other Changes**
* Experimental support for printf format specifications (work in progress):
.. code:: c++
fmt::printf("The answer is %d.", 42);
std::string s = fmt::sprintf("Look, a %s!", "string");
* Support for hexadecimal floating point format specifiers ``a`` and ``A``:
.. code:: c++
print("{:a}", -42.0); // Prints -0x1.5p+5
print("{:A}", -42.0); // Prints -0X1.5P+5
* CMake option ``FMT_SHARED`` that specifies whether to build format as a
shared library (off by default).
0.9.0 - 2014-05-13
------------------
* More efficient implementation of variadic formatting functions.
* ``Writer::Format`` now has a variadic overload:
.. code:: c++
Writer out;
out.Format("Look, I'm {}!", "variadic");
* For efficiency and consistency with other overloads, variadic overload of
the ``Format`` function now returns ``Writer`` instead of ``std::string``.
Use the ``str`` function to convert it to ``std::string``:
.. code:: c++
std::string s = str(Format("Look, I'm {}!", "variadic"));
* Replaced formatter actions with output sinks: ``NoAction`` -> ``NullSink``,
``Write`` -> ``FileSink``, ``ColorWriter`` -> ``ANSITerminalSink``.
This improves naming consistency and shouldn't affect client code unless
these classes are used directly which should be rarely needed.
* Added ``ThrowSystemError`` function that formats a message and throws
``SystemError`` containing the formatted message and system-specific error
description. For example, the following code
.. code:: c++
FILE *f = fopen(filename, "r");
if (!f)
ThrowSystemError(errno, "Failed to open file '{}'") << filename;
will throw ``SystemError`` exception with description
"Failed to open file '<filename>': No such file or directory" if file
doesn't exist.
* Support for AppVeyor continuous integration platform.
* ``Format`` now throws ``SystemError`` in case of I/O errors.
* Improve test infrastructure. Print functions are now tested by redirecting
the output to a pipe.
0.8.0 - 2014-04-14
------------------
* Initial release