std::basic_format_parse_context
Defined in header <format> |
||
|---|---|---|
template<class CharT> class basic_format_parse_context; |
(1) | (since C++20) |
using format_parse_context = basic_format_parse_context<char>; |
(2) | (since C++20) |
using wformat_parse_context = basic_format_parse_context<wchar_t>; |
(3) | (since C++20) |
Provides access to the format string parsing state consisting of the format string range being parsed and the argument counter for automatic indexing.
A basic_format_parse_context instance is passed to Formatter when parsing the format specification.
Member types
| Type | Definition |
|---|---|
char_type |
CharT |
iterator |
std::basic_string_view<CharT>::const_iterator |
const_iterator |
std::basic_string_view<CharT>::const_iterator |
Member functions
|
(constructor)
|
constructs a std::basic_format_parse_context instance from format string and argument count (public member function) |
|
operator=
[deleted]
|
std::basic_format_parse_context is not copyable (public member function) |
|
begin
|
returns an iterator to the beginning of the format string range (public member function) |
|
end
|
returns an iterator to the end of the format string range (public member function) |
|
advance_to
|
advances the begin iterator to the given position (public member function) |
|
next_arg_id
|
enters automatic indexing mode, and returns the next argument index (public member function) |
|
check_arg_id
|
enters manual indexing mode, checks if the given argument index is in range (public member function) |
std::basic_format_parse_context::basic_format_parse_context
constexpr explicit basic_format_parse_context(std::basic_string_view<CharT> fmt,
std::size_t num_args = 0) noexcept; |
(1) | |
basic_format_parse_context(const basic_format_parse_context&) = delete; |
(2) |
std::basic_format_parse_context instance. Initializes the format string range to
[fmt.begin(), fmt.end()), and the argument count to
num_args.
std::basic_format_parse_context is not copyable.
std::basic_format_parse_context::begin
constexpr const_iterator begin() const noexcept; |
Returns an iterator to the beginning of the format string range.
std::basic_format_parse_context::end
constexpr const_iterator end() const noexcept; |
Returns an iterator to the end of the format string range.
std::basic_format_parse_context::advance_to
constexpr void advance_to(const_iterator it); |
Sets the beginning of the format string range to it. After a call to advance_to, subsequent calls to begin() will return a copy of it.
The behavior is undefined if end() is not reachable from it.
std::basic_format_parse_context::next_arg_id
constexpr std::size_t next_arg_id(); |
Enters automatic argument indexing mode, and returns the next argument index, starting from 0.
If *this has already entered manual argument indexing mode, throws std::format_error.
std::basic_format_parse_context::check_arg_id
constexpr void check_arg_id(std::size_t id); |
Enters manual argument indexing mode.
If *this has already entered automatic argument indexing mode, throws std::format_error.
If id is larger than or equal to the argument count provided in the constructor, the call is not a constant expression.
Example
See also
© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
https://en.cppreference.com/w/cpp/utility/format/basic_format_parse_context
