fmt/test/base-test.cc
2024-06-22 11:10:54 -07:00

882 lines
27 KiB
C++

// Formatting library for C++ - core tests
//
// Copyright (c) 2012 - present, Victor Zverovich
// All rights reserved.
//
// For the license information refer to format.h.
// clang-format off
#include "test-assert.h"
// clang-format on
#include "fmt/base.h"
#include <climits> // INT_MAX
#include <cstring> // std::strlen
#include <functional> // std::equal_to
#include <iterator> // std::back_insert_iterator, std::distance
#include <limits> // std::numeric_limits
#include <string> // std::string
#include <type_traits> // std::is_same
#include "gmock/gmock.h"
using fmt::string_view;
using fmt::detail::buffer;
using testing::_;
using testing::Invoke;
using testing::Return;
#ifdef FMT_FORMAT_H_
# error core-test includes format.h
#endif
fmt::appender copy(fmt::string_view s, fmt::appender out) {
for (char c : s) *out++ = c;
return out;
}
TEST(string_view_test, value_type) {
static_assert(std::is_same<string_view::value_type, char>::value, "");
}
TEST(string_view_test, ctor) {
EXPECT_STREQ("abc", fmt::string_view("abc").data());
EXPECT_EQ(3u, fmt::string_view("abc").size());
EXPECT_STREQ("defg", fmt::string_view(std::string("defg")).data());
EXPECT_EQ(4u, fmt::string_view(std::string("defg")).size());
}
TEST(string_view_test, length) {
// Test that string_view::size() returns string length, not buffer size.
char str[100] = "some string";
EXPECT_EQ(std::strlen(str), string_view(str).size());
EXPECT_LT(std::strlen(str), sizeof(str));
}
// Check string_view's comparison operator.
template <template <typename> class Op> void check_op() {
const char* inputs[] = {"foo", "fop", "fo"};
size_t num_inputs = sizeof(inputs) / sizeof(*inputs);
for (size_t i = 0; i < num_inputs; ++i) {
for (size_t j = 0; j < num_inputs; ++j) {
string_view lhs(inputs[i]), rhs(inputs[j]);
EXPECT_EQ(Op<int>()(lhs.compare(rhs), 0), Op<string_view>()(lhs, rhs));
}
}
}
TEST(string_view_test, compare) {
EXPECT_EQ(string_view("foo").compare(string_view("foo")), 0);
EXPECT_GT(string_view("fop").compare(string_view("foo")), 0);
EXPECT_LT(string_view("foo").compare(string_view("fop")), 0);
EXPECT_GT(string_view("foo").compare(string_view("fo")), 0);
EXPECT_LT(string_view("fo").compare(string_view("foo")), 0);
EXPECT_TRUE(string_view("foo").starts_with('f'));
EXPECT_FALSE(string_view("foo").starts_with('o'));
EXPECT_FALSE(string_view().starts_with('o'));
EXPECT_TRUE(string_view("foo").starts_with("fo"));
EXPECT_TRUE(string_view("foo").starts_with("foo"));
EXPECT_FALSE(string_view("foo").starts_with("fooo"));
EXPECT_FALSE(string_view().starts_with("fooo"));
check_op<std::equal_to>();
check_op<std::not_equal_to>();
check_op<std::less>();
check_op<std::less_equal>();
check_op<std::greater>();
check_op<std::greater_equal>();
}
TEST(base_test, is_output_iterator) {
EXPECT_TRUE((fmt::detail::is_output_iterator<char*, char>::value));
EXPECT_FALSE((fmt::detail::is_output_iterator<const char*, char>::value));
EXPECT_FALSE((fmt::detail::is_output_iterator<std::string, char>::value));
EXPECT_TRUE(
(fmt::detail::is_output_iterator<std::back_insert_iterator<std::string>,
char>::value));
EXPECT_TRUE(
(fmt::detail::is_output_iterator<std::string::iterator, char>::value));
EXPECT_FALSE((fmt::detail::is_output_iterator<std::string::const_iterator,
char>::value));
}
TEST(base_test, is_back_insert_iterator) {
EXPECT_TRUE(fmt::detail::is_back_insert_iterator<
std::back_insert_iterator<std::string>>::value);
EXPECT_FALSE(fmt::detail::is_back_insert_iterator<
std::front_insert_iterator<std::string>>::value);
}
TEST(base_test, buffer_appender) {
#ifdef __cpp_lib_ranges
static_assert(std::output_iterator<fmt::appender, char>);
#endif
}
#if !FMT_GCC_VERSION || FMT_GCC_VERSION >= 470
TEST(buffer_test, noncopyable) {
EXPECT_FALSE(std::is_copy_constructible<buffer<char>>::value);
# if !FMT_MSC_VERSION
// std::is_copy_assignable is broken in MSVC2013.
EXPECT_FALSE(std::is_copy_assignable<buffer<char>>::value);
# endif
}
TEST(buffer_test, nonmoveable) {
EXPECT_FALSE(std::is_move_constructible<buffer<char>>::value);
# if !FMT_MSC_VERSION
// std::is_move_assignable is broken in MSVC2013.
EXPECT_FALSE(std::is_move_assignable<buffer<char>>::value);
# endif
}
#endif
TEST(buffer_test, indestructible) {
static_assert(!std::is_destructible<fmt::detail::buffer<int>>(),
"buffer's destructor is protected");
}
template <typename T> struct mock_buffer final : buffer<T> {
MOCK_METHOD(size_t, do_grow, (size_t));
static void grow(buffer<T>& buf, size_t capacity) {
auto& self = static_cast<mock_buffer&>(buf);
self.set(buf.data(), self.do_grow(capacity));
}
mock_buffer(T* data = nullptr, size_t buf_capacity = 0) : buffer<T>(grow) {
this->set(data, buf_capacity);
ON_CALL(*this, do_grow(_)).WillByDefault(Invoke([](size_t capacity) {
return capacity;
}));
}
};
TEST(buffer_test, ctor) {
{
mock_buffer<int> buffer;
EXPECT_EQ(nullptr, buffer.data());
EXPECT_EQ(static_cast<size_t>(0), buffer.size());
EXPECT_EQ(static_cast<size_t>(0), buffer.capacity());
}
{
int dummy;
mock_buffer<int> buffer(&dummy);
EXPECT_EQ(&dummy, &buffer[0]);
EXPECT_EQ(static_cast<size_t>(0), buffer.size());
EXPECT_EQ(static_cast<size_t>(0), buffer.capacity());
}
{
int dummy;
size_t capacity = std::numeric_limits<size_t>::max();
mock_buffer<int> buffer(&dummy, capacity);
EXPECT_EQ(&dummy, &buffer[0]);
EXPECT_EQ(static_cast<size_t>(0), buffer.size());
EXPECT_EQ(capacity, buffer.capacity());
}
}
TEST(buffer_test, access) {
char data[10];
mock_buffer<char> buffer(data, sizeof(data));
buffer[0] = 11;
EXPECT_EQ(11, buffer[0]);
buffer[3] = 42;
EXPECT_EQ(42, *(&buffer[0] + 3));
const fmt::detail::buffer<char>& const_buffer = buffer;
EXPECT_EQ(42, const_buffer[3]);
}
TEST(buffer_test, try_resize) {
char data[123];
mock_buffer<char> buffer(data, sizeof(data));
buffer[10] = 42;
EXPECT_EQ(42, buffer[10]);
buffer.try_resize(20);
EXPECT_EQ(20u, buffer.size());
EXPECT_EQ(123u, buffer.capacity());
EXPECT_EQ(42, buffer[10]);
buffer.try_resize(5);
EXPECT_EQ(5u, buffer.size());
EXPECT_EQ(123u, buffer.capacity());
EXPECT_EQ(42, buffer[10]);
// Check if try_resize calls grow.
EXPECT_CALL(buffer, do_grow(124));
buffer.try_resize(124);
EXPECT_CALL(buffer, do_grow(200));
buffer.try_resize(200);
}
TEST(buffer_test, try_resize_partial) {
char data[10];
mock_buffer<char> buffer(data, sizeof(data));
EXPECT_CALL(buffer, do_grow(20)).WillOnce(Return(15));
buffer.try_resize(20);
EXPECT_EQ(buffer.capacity(), 15);
EXPECT_EQ(buffer.size(), 15);
}
TEST(buffer_test, clear) {
mock_buffer<char> buffer;
EXPECT_CALL(buffer, do_grow(20));
buffer.try_resize(20);
buffer.try_resize(0);
EXPECT_EQ(static_cast<size_t>(0), buffer.size());
EXPECT_EQ(20u, buffer.capacity());
}
TEST(buffer_test, append) {
char data[15];
mock_buffer<char> buffer(data, 10);
auto test = "test";
buffer.append(test, test + 5);
EXPECT_STREQ(test, &buffer[0]);
EXPECT_EQ(5u, buffer.size());
buffer.try_resize(10);
EXPECT_CALL(buffer, do_grow(12));
buffer.append(test, test + 2);
EXPECT_EQ('t', buffer[10]);
EXPECT_EQ('e', buffer[11]);
EXPECT_EQ(12u, buffer.size());
}
TEST(buffer_test, append_partial) {
char data[10];
mock_buffer<char> buffer(data, sizeof(data));
testing::InSequence seq;
EXPECT_CALL(buffer, do_grow(15)).WillOnce(Return(10));
EXPECT_CALL(buffer, do_grow(15)).WillOnce(Invoke([&buffer](size_t) {
EXPECT_EQ(fmt::string_view(buffer.data(), buffer.size()), "0123456789");
buffer.clear();
return 10;
}));
auto test = "0123456789abcde";
buffer.append(test, test + 15);
}
TEST(buffer_test, append_allocates_enough_storage) {
char data[19];
mock_buffer<char> buffer(data, 10);
auto test = "abcdefgh";
buffer.try_resize(10);
EXPECT_CALL(buffer, do_grow(19));
buffer.append(test, test + 9);
}
struct custom_context {
using char_type = char;
using parse_context_type = fmt::format_parse_context;
bool called = false;
template <typename T> struct formatter_type {
FMT_CONSTEXPR auto parse(fmt::format_parse_context& ctx)
-> decltype(ctx.begin()) {
return ctx.begin();
}
const char* format(const T&, custom_context& ctx) const {
ctx.called = true;
return nullptr;
}
};
void advance_to(const char*) {}
};
struct test_struct {};
FMT_BEGIN_NAMESPACE
template <typename Char> struct formatter<test_struct, Char> {
FMT_CONSTEXPR auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
return ctx.begin();
}
auto format(test_struct, format_context& ctx) const -> decltype(ctx.out()) {
return copy("test", ctx.out());
}
};
FMT_END_NAMESPACE
TEST(arg_test, format_args) {
auto args = fmt::format_args();
EXPECT_FALSE(args.get(1));
}
TEST(arg_test, make_value_with_custom_context) {
auto t = test_struct();
auto arg = fmt::detail::value<custom_context>(
fmt::detail::arg_mapper<custom_context>().map(t));
auto ctx = custom_context();
auto parse_ctx = fmt::format_parse_context("");
arg.custom.format(&t, parse_ctx, ctx);
EXPECT_TRUE(ctx.called);
}
// Use a unique result type to make sure that there are no undesirable
// conversions.
struct test_result {};
template <typename T> struct mock_visitor {
template <typename U> struct result {
using type = test_result;
};
mock_visitor() {
ON_CALL(*this, visit(_)).WillByDefault(Return(test_result()));
}
MOCK_METHOD(test_result, visit, (T));
MOCK_METHOD(void, unexpected, ());
auto operator()(T value) -> test_result { return visit(value); }
template <typename U> auto operator()(U) -> test_result {
unexpected();
return test_result();
}
};
template <typename T> struct visit_type {
using type = T;
};
#define VISIT_TYPE(type_, visit_type_) \
template <> struct visit_type<type_> { \
using type = visit_type_; \
}
VISIT_TYPE(signed char, int);
VISIT_TYPE(unsigned char, unsigned);
VISIT_TYPE(short, int);
VISIT_TYPE(unsigned short, unsigned);
#if LONG_MAX == INT_MAX
VISIT_TYPE(long, int);
VISIT_TYPE(unsigned long, unsigned);
#else
VISIT_TYPE(long, long long);
VISIT_TYPE(unsigned long, unsigned long long);
#endif
#define CHECK_ARG(Char, expected, value) \
{ \
testing::StrictMock<mock_visitor<decltype(expected)>> visitor; \
EXPECT_CALL(visitor, visit(expected)); \
using iterator = fmt::basic_appender<Char>; \
auto var = value; \
fmt::detail::make_arg<fmt::basic_format_context<iterator, Char>>(var) \
.visit(visitor); \
}
#define CHECK_ARG_SIMPLE(value) \
{ \
using value_type = decltype(value); \
typename visit_type<value_type>::type expected = value; \
CHECK_ARG(char, expected, value) \
}
template <typename T> class numeric_arg_test : public testing::Test {};
using test_types =
testing::Types<bool, signed char, unsigned char, short, unsigned short, int,
unsigned, long, unsigned long, long long, unsigned long long,
float, double, long double>;
TYPED_TEST_SUITE(numeric_arg_test, test_types);
template <typename T, fmt::enable_if_t<std::is_integral<T>::value, int> = 0>
auto test_value() -> T {
return static_cast<T>(42);
}
template <typename T,
fmt::enable_if_t<std::is_floating_point<T>::value, int> = 0>
auto test_value() -> T {
return static_cast<T>(4.2);
}
TYPED_TEST(numeric_arg_test, make_and_visit) {
CHECK_ARG_SIMPLE(test_value<TypeParam>());
CHECK_ARG_SIMPLE(std::numeric_limits<TypeParam>::min());
CHECK_ARG_SIMPLE(std::numeric_limits<TypeParam>::max());
}
TEST(arg_test, char_arg) { CHECK_ARG(char, 'a', 'a'); }
TEST(arg_test, string_arg) {
char str_data[] = "test";
char* str = str_data;
const char* cstr = str;
CHECK_ARG(char, cstr, str);
auto sv = fmt::string_view(str);
CHECK_ARG(char, sv, std::string(str));
}
TEST(arg_test, pointer_arg) {
void* p = nullptr;
const void* cp = nullptr;
CHECK_ARG(char, cp, p);
CHECK_ARG_SIMPLE(cp);
}
struct check_custom {
auto operator()(fmt::basic_format_arg<fmt::format_context>::handle h) const
-> test_result {
struct test_buffer final : fmt::detail::buffer<char> {
char data[10];
test_buffer()
: fmt::detail::buffer<char>([](buffer<char>&, size_t) {}, data, 0,
10) {}
} buffer;
auto parse_ctx = fmt::format_parse_context("");
auto ctx = fmt::format_context(fmt::appender(buffer), fmt::format_args());
h.format(parse_ctx, ctx);
EXPECT_EQ("test", std::string(buffer.data, buffer.size()));
return test_result();
}
};
TEST(arg_test, custom_arg) {
auto test = test_struct();
using visitor =
mock_visitor<fmt::basic_format_arg<fmt::format_context>::handle>;
auto&& v = testing::StrictMock<visitor>();
EXPECT_CALL(v, visit(_)).WillOnce(Invoke(check_custom()));
fmt::detail::make_arg<fmt::format_context>(test).visit(v);
}
TEST(arg_test, visit_invalid_arg) {
auto&& visitor = testing::StrictMock<mock_visitor<fmt::monostate>>();
EXPECT_CALL(visitor, visit(_));
fmt::basic_format_arg<fmt::format_context>().visit(visitor);
}
#if FMT_USE_CONSTEXPR
enum class arg_id_result { none, empty, index, name };
struct test_arg_id_handler {
arg_id_result res = arg_id_result::none;
int index = 0;
string_view name;
constexpr void on_auto() { res = arg_id_result::empty; }
constexpr void on_index(int i) {
res = arg_id_result::index;
index = i;
}
constexpr void on_name(string_view n) {
res = arg_id_result::name;
name = n;
}
};
template <size_t N>
constexpr test_arg_id_handler parse_arg_id(const char (&s)[N]) {
auto h = test_arg_id_handler();
fmt::detail::parse_arg_id(s, s + N, h);
return h;
}
TEST(base_test, constexpr_parse_arg_id) {
static_assert(parse_arg_id(":").res == arg_id_result::empty, "");
static_assert(parse_arg_id("}").res == arg_id_result::empty, "");
static_assert(parse_arg_id("42:").res == arg_id_result::index, "");
static_assert(parse_arg_id("42:").index == 42, "");
static_assert(parse_arg_id("foo:").res == arg_id_result::name, "");
static_assert(parse_arg_id("foo:").name.size() == 3, "");
}
template <size_t N> constexpr auto parse_test_specs(const char (&s)[N]) {
auto ctx = fmt::detail::compile_parse_context<char>(fmt::string_view(s, N),
43, nullptr);
auto specs = fmt::detail::dynamic_format_specs<>();
fmt::detail::parse_format_specs(s, s + N - 1, specs, ctx,
fmt::detail::type::float_type);
return specs;
}
TEST(base_test, constexpr_parse_format_specs) {
static_assert(parse_test_specs("<").align == fmt::align::left, "");
static_assert(parse_test_specs("*^").fill.get<char>() == '*', "");
static_assert(parse_test_specs("+").sign == fmt::sign::plus, "");
static_assert(parse_test_specs("-").sign == fmt::sign::minus, "");
static_assert(parse_test_specs(" ").sign == fmt::sign::space, "");
static_assert(parse_test_specs("#").alt, "");
static_assert(parse_test_specs("0").align == fmt::align::numeric, "");
static_assert(parse_test_specs("L").localized, "");
static_assert(parse_test_specs("42").width == 42, "");
static_assert(parse_test_specs("{42}").width_ref.val.index == 42, "");
static_assert(parse_test_specs(".42").precision == 42, "");
static_assert(parse_test_specs(".{42}").precision_ref.val.index == 42, "");
static_assert(parse_test_specs("f").type == fmt::presentation_type::fixed,
"");
}
struct test_format_string_handler {
constexpr void on_text(const char*, const char*) {}
constexpr auto on_arg_id() -> int { return 0; }
template <typename T> constexpr auto on_arg_id(T) -> int { return 0; }
constexpr void on_replacement_field(int, const char*) {}
constexpr auto on_format_specs(int, const char* begin, const char*) -> const
char* {
return begin;
}
constexpr void on_error(const char*) { error = true; }
bool error = false;
};
template <size_t N> constexpr bool parse_string(const char (&s)[N]) {
auto h = test_format_string_handler();
fmt::detail::parse_format_string<true>(fmt::string_view(s, N - 1), h);
return !h.error;
}
TEST(base_test, constexpr_parse_format_string) {
static_assert(parse_string("foo"), "");
static_assert(!parse_string("}"), "");
static_assert(parse_string("{}"), "");
static_assert(parse_string("{42}"), "");
static_assert(parse_string("{foo}"), "");
static_assert(parse_string("{:}"), "");
}
#endif // FMT_USE_CONSTEXPR
struct enabled_formatter {};
struct enabled_ptr_formatter {};
struct disabled_formatter {};
struct disabled_formatter_convertible {
operator int() const { return 42; }
};
FMT_BEGIN_NAMESPACE
template <> struct formatter<enabled_formatter> {
FMT_CONSTEXPR auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
return ctx.begin();
}
auto format(enabled_formatter, format_context& ctx) const
-> decltype(ctx.out()) {
return ctx.out();
}
};
template <> struct formatter<enabled_ptr_formatter*> {
FMT_CONSTEXPR auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
return ctx.begin();
}
auto format(enabled_ptr_formatter*, format_context& ctx) const
-> decltype(ctx.out()) {
return ctx.out();
}
};
FMT_END_NAMESPACE
TEST(base_test, has_formatter) {
using fmt::has_formatter;
using context = fmt::format_context;
static_assert(has_formatter<enabled_formatter, context>::value, "");
static_assert(!has_formatter<disabled_formatter, context>::value, "");
static_assert(!has_formatter<disabled_formatter_convertible, context>::value,
"");
}
struct const_formattable {};
struct nonconst_formattable {};
FMT_BEGIN_NAMESPACE
template <> struct formatter<const_formattable> {
FMT_CONSTEXPR auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
return ctx.begin();
}
auto format(const const_formattable&, format_context& ctx) const
-> decltype(ctx.out()) {
return copy("test", ctx.out());
}
};
template <> struct formatter<nonconst_formattable> {
FMT_CONSTEXPR auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
return ctx.begin();
}
auto format(nonconst_formattable&, format_context& ctx) const
-> decltype(ctx.out()) {
return copy("test", ctx.out());
}
};
FMT_END_NAMESPACE
struct convertible_to_pointer {
operator const int*() const { return nullptr; }
};
struct convertible_to_pointer_formattable {
operator const int*() const { return nullptr; }
};
FMT_BEGIN_NAMESPACE
template <> struct formatter<convertible_to_pointer_formattable> {
FMT_CONSTEXPR auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
return ctx.begin();
}
auto format(convertible_to_pointer_formattable, format_context& ctx) const
-> decltype(ctx.out()) {
return copy("test", ctx.out());
}
};
FMT_END_NAMESPACE
enum class unformattable_scoped_enum {};
TEST(base_test, is_formattable) {
static_assert(!fmt::is_formattable<wchar_t>::value, "");
#ifdef __cpp_char8_t
static_assert(!fmt::is_formattable<char8_t>::value, "");
#endif
static_assert(!fmt::is_formattable<char16_t>::value, "");
static_assert(!fmt::is_formattable<char32_t>::value, "");
static_assert(!fmt::is_formattable<signed char*>::value, "");
static_assert(!fmt::is_formattable<unsigned char*>::value, "");
static_assert(!fmt::is_formattable<const signed char*>::value, "");
static_assert(!fmt::is_formattable<const unsigned char*>::value, "");
static_assert(!fmt::is_formattable<const wchar_t*>::value, "");
static_assert(!fmt::is_formattable<const wchar_t[3]>::value, "");
static_assert(!fmt::is_formattable<fmt::basic_string_view<wchar_t>>::value,
"");
static_assert(fmt::is_formattable<enabled_formatter>::value, "");
static_assert(!fmt::is_formattable<enabled_ptr_formatter*>::value, "");
static_assert(!fmt::is_formattable<disabled_formatter>::value, "");
static_assert(!fmt::is_formattable<disabled_formatter_convertible>::value,
"");
static_assert(fmt::is_formattable<const_formattable&>::value, "");
static_assert(fmt::is_formattable<const const_formattable&>::value, "");
static_assert(fmt::is_formattable<nonconst_formattable&>::value, "");
#if !FMT_MSC_VERSION || FMT_MSC_VERSION >= 1910
static_assert(!fmt::is_formattable<const nonconst_formattable&>::value, "");
#endif
static_assert(!fmt::is_formattable<convertible_to_pointer>::value, "");
const auto f = convertible_to_pointer_formattable();
auto str = std::string();
fmt::format_to(std::back_inserter(str), "{}", f);
EXPECT_EQ(str, "test");
static_assert(!fmt::is_formattable<void (*)()>::value, "");
struct s;
static_assert(!fmt::is_formattable<int(s::*)>::value, "");
static_assert(!fmt::is_formattable<int (s::*)()>::value, "");
static_assert(!fmt::is_formattable<unformattable_scoped_enum>::value, "");
static_assert(!fmt::is_formattable<unformattable_scoped_enum>::value, "");
}
#if FMT_USE_CONCEPTS
TEST(base_test, formattable) {
static_assert(fmt::formattable<char>);
static_assert(fmt::formattable<char&>);
static_assert(fmt::formattable<char&&>);
static_assert(fmt::formattable<const char>);
static_assert(fmt::formattable<const char&>);
static_assert(fmt::formattable<const char&&>);
static_assert(fmt::formattable<int>);
static_assert(!fmt::formattable<wchar_t>);
}
#endif
TEST(base_test, format_to) {
auto s = std::string();
fmt::format_to(std::back_inserter(s), "{}", 42);
EXPECT_EQ(s, "42");
}
TEST(base_test, format_to_array) {
char buffer[4];
auto result = fmt::format_to(buffer, "{}", 12345);
EXPECT_EQ(4, std::distance(&buffer[0], result.out));
EXPECT_TRUE(result.truncated);
EXPECT_EQ(buffer + 4, result.out);
EXPECT_EQ("1234", fmt::string_view(buffer, 4));
char* out = nullptr;
EXPECT_THROW(out = result, std::runtime_error);
(void)out;
result = fmt::format_to(buffer, "{:s}", "foobar");
EXPECT_EQ(4, std::distance(&buffer[0], result.out));
EXPECT_TRUE(result.truncated);
EXPECT_EQ(buffer + 4, result.out);
EXPECT_EQ("foob", fmt::string_view(buffer, 4));
buffer[0] = 'x';
buffer[1] = 'x';
buffer[2] = 'x';
buffer[3] = 'x';
result = fmt::format_to(buffer, "{}", 'A');
EXPECT_EQ(1, std::distance(&buffer[0], result.out));
EXPECT_FALSE(result.truncated);
EXPECT_EQ(buffer + 1, result.out);
EXPECT_EQ("Axxx", fmt::string_view(buffer, 4));
result = fmt::format_to(buffer, "{}{} ", 'B', 'C');
EXPECT_EQ(3, std::distance(&buffer[0], result.out));
EXPECT_FALSE(result.truncated);
EXPECT_EQ(buffer + 3, result.out);
EXPECT_EQ("BC x", fmt::string_view(buffer, 4));
result = fmt::format_to(buffer, "{}", "ABCDE");
EXPECT_EQ(4, std::distance(&buffer[0], result.out));
EXPECT_TRUE(result.truncated);
EXPECT_EQ("ABCD", fmt::string_view(buffer, 4));
result = fmt::format_to(buffer, "{}", std::string(1000, '*'));
EXPECT_EQ(4, std::distance(&buffer[0], result.out));
EXPECT_TRUE(result.truncated);
EXPECT_EQ("****", fmt::string_view(buffer, 4));
}
#ifdef __cpp_lib_byte
TEST(base_test, format_byte) {
auto s = std::string();
fmt::format_to(std::back_inserter(s), "{}", std::byte(42));
EXPECT_EQ(s, "42");
}
#endif
// Test that check is not found by ADL.
template <typename T> void check(T);
TEST(base_test, adl_check) {
auto s = std::string();
fmt::format_to(std::back_inserter(s), "{}", test_struct());
EXPECT_EQ(s, "test");
}
struct implicitly_convertible_to_string_view {
operator fmt::string_view() const { return "foo"; }
};
TEST(base_test, no_implicit_conversion_to_string_view) {
EXPECT_FALSE(
fmt::is_formattable<implicitly_convertible_to_string_view>::value);
}
#ifdef FMT_USE_STRING_VIEW
struct implicitly_convertible_to_std_string_view {
operator std::string_view() const { return "foo"; }
};
TEST(base_test, no_implicit_conversion_to_std_string_view) {
EXPECT_FALSE(
fmt::is_formattable<implicitly_convertible_to_std_string_view>::value);
}
#endif
// std::is_constructible is broken in MSVC until version 2015.
#if !FMT_MSC_VERSION || FMT_MSC_VERSION >= 1900
struct explicitly_convertible_to_string_view {
explicit operator fmt::string_view() const { return "foo"; }
};
TEST(base_test, format_explicitly_convertible_to_string_view) {
// Types explicitly convertible to string_view are not formattable by
// default because it may introduce ODR violations.
static_assert(
!fmt::is_formattable<explicitly_convertible_to_string_view>::value, "");
}
# ifdef FMT_USE_STRING_VIEW
struct explicitly_convertible_to_std_string_view {
explicit operator std::string_view() const { return "foo"; }
};
TEST(base_test, format_explicitly_convertible_to_std_string_view) {
// Types explicitly convertible to string_view are not formattable by
// default because it may introduce ODR violations.
static_assert(
!fmt::is_formattable<explicitly_convertible_to_std_string_view>::value,
"");
}
# endif
#endif
TEST(base_test, has_const_formatter) {
EXPECT_TRUE((fmt::detail::has_const_formatter<const_formattable,
fmt::format_context>()));
EXPECT_FALSE((fmt::detail::has_const_formatter<nonconst_formattable,
fmt::format_context>()));
}
TEST(base_test, format_nonconst) {
auto s = std::string();
fmt::format_to(std::back_inserter(s), "{}", nonconst_formattable());
EXPECT_EQ(s, "test");
}
TEST(base_test, throw_in_buffer_dtor) {
enum { buffer_size = 256 };
struct throwing_iterator {
int& count;
auto operator=(char) -> throwing_iterator& {
if (++count > buffer_size) throw std::exception();
return *this;
}
auto operator*() -> throwing_iterator& { return *this; }
auto operator++() -> throwing_iterator& { return *this; }
auto operator++(int) -> throwing_iterator { return *this; }
};
try {
int count = 0;
fmt::format_to(throwing_iterator{count}, fmt::runtime("{:{}}{"), "",
buffer_size + 1);
} catch (const std::exception&) {
}
}
struct its_a_trap {
template <typename T> operator T() const {
auto v = T();
v.x = 42;
return v;
}
};
FMT_BEGIN_NAMESPACE
template <> struct formatter<its_a_trap> {
FMT_CONSTEXPR auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
return ctx.begin();
}
auto format(its_a_trap, format_context& ctx) const
-> decltype(ctx.out()) const {
auto out = ctx.out();
*out++ = 'x';
return out;
}
};
FMT_END_NAMESPACE
TEST(base_test, trappy_conversion) {
auto s = std::string();
fmt::format_to(std::back_inserter(s), "{}", its_a_trap());
EXPECT_EQ(s, "x");
}