mirror/fmt
1
0
Fork 0
mirror of https://github.com/fmtlib/fmt.git synced 2024-12-25 15:21:54 +00:00
Code Issues Packages Projects Releases Wiki Activity

Simplify counting iterators

Browse Source
This commit is contained in:
Victor Zverovich 2018-03-31 07:47:30 -10:00
parent e8e006f4e7
commit 4975297eb0
1 changed files with 15 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
include/fmt/format.h
View File

@ -702,7 +702,7 @@ FMT_CONSTEXPR const Char *pointer_from(null_terminating_iterator<Char> it) {
template <typename T>
class counting_iterator {
private:
std::size_t* count_;
std::size_t count_;
mutable T blackhole_;
public:
@ -712,10 +712,12 @@ class counting_iterator {
typedef T* pointer;
typedef T& reference;
explicit counting_iterator(std::size_t &count): count_(&count) {}
counting_iterator(): count_(0) {}
std::size_t count() const { return count_; }
counting_iterator& operator++() {
++*count_;
++count_;
return *this;
}
@ -733,7 +735,7 @@ class truncating_iterator {
OutputIt out_;
std::size_t limit_;
std::size_t *count_;
std::size_t count_;
mutable typename traits::value_type blackhole_;
public:
@ -743,20 +745,21 @@ class truncating_iterator {
typedef typename traits::pointer pointer;
typedef typename traits::reference reference;
truncating_iterator(OutputIt out, std::size_t limit, std::size_t &count)
: out_(out), limit_(limit), count_(&count) {}
truncating_iterator(OutputIt out, std::size_t limit)
: out_(out), limit_(limit), count_(0) {}
OutputIt base() const { return out_; }
std::size_t count() const { return count_; }
truncating_iterator& operator++() {
if ((*count_)++ < limit_)
if (count_++ < limit_)
++out_;
return *this;
}
truncating_iterator operator++(int) { return ++*this; }
reference operator*() const { return *count_ < limit_ ? *out_ : blackhole_; }
reference operator*() const { return count_ < limit_ ? *out_ : blackhole_; }
};
// Returns true if value is negative, false otherwise.
@ -3436,10 +3439,9 @@ template <typename OutputIt, typename... Args>
inline format_to_n_result<OutputIt> format_to_n(
OutputIt out, std::size_t n, string_view format_str, const Args & ... args) {
typedef internal::truncating_iterator<OutputIt> It;
std::size_t count = 0;
auto it = vformat_to(It(out, n, count), format_str,
auto it = vformat_to(It(out, n), format_str,
*make_args<typename context_t<It>::type>(args...));
return {it.base(), count};
return {it.base(), it.count()};
}
inline std::string vformat(string_view format_str, format_args args) {
@ -3472,10 +3474,8 @@ inline typename std::enable_if<internal::is_format_string<String>::value>::type
// Counts the number of characters in the output of format(format_str, args...).
template <typename... Args>
inline std::size_t count(string_view format_str, const Args & ... args) {
std::size_t size = 0;
internal::counting_iterator<char> it(size);
format_to(it, format_str, args...);
return size;
auto it = format_to(internal::counting_iterator<char>(), format_str, args...);
return it.count();
}
} // namespace fmt