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C++ named requirements: RegexTraits (since C++11)

RegexTraits is a traits class that abstracts operations needed for a given character type when as template type parameters for std::basic_regex.

Requirements

Given.

CharT, a character type
X, a RegexTraits type for type CharT
u, an object of type X
v, an object of type const X
p, a value of type const CharT*
I1, I2, input iterators
F1, F2, forward iterators
c, a value of type const CharT
s, an object of type X::string_type
cs, an object of type const X::string_type
b, a value of type bool
I, a value of type int
cl, an object of type X::char_class_type
loc, an object of type X::locale_type

expression	return type	semantics
`X::char_type`	`CharT`	Used to refer to the character type.
`X::string_type`	`std::basic_string<CharT>`
`X::locale_type`		A CopyConstructible type that represents the locale used by the traits class.
`X::char_class_type`		A BitmaskType type that represents a particular character classification.
`X::length(p)`	`std::size_t`	Returns: the smallest `i` such that `p[i] == 0`. Complexity is linear in `i`.
`v.translate(c)`	`X::char_type`	Returns: a character such that for any character `d` considered to be equivalent to `c`, then `v.translate(c) == v.translate(d)`.
`v.translate_nocase(c)`	`X::char_type`	Returns: a character such that for any character `C` considered to be equivalent to `c` without regard to case, then `v.translate_nocase(c) == v.translate_nocase(C)`.
`v.transform(F1, F2)`	`X::string_type`	Returns: a sort key for the character sequence designated by the iterator range `[F1, F2)` such that if the character sequence `[G1, G2)` sorts before the character sequence `[H1, H2)`, then `v.transform(G1, G2) < v.transform(H1, H2)`.
`v.transform_primary(F1, F2)`	`X::string_type`	Returns: a sort key for the character sequence designated by the iterator range `[F1, F2)` such that if the character sequence `[G1, G2)` sorts before the character sequence `[H1, H2)` without regard to case, then `v.transform_primary(G1, G2) < v.transform_primary(H1, H2)`.
`v.lookup_collatename(F1, F2)`	`X::string_type`	Returns: An empty string if the character sequence is not a valid collating element A sequence of characters that represents the collating element consisting of the character sequence designated by the iterator range `[F1, F2)` otherwise
`v.lookup_classname(F1, F2, b)`	`X::char_class_type`	Converts the character sequence designated by the iterator range `[F1, F2)` into a value of a BitmaskType that can subsequently be passed to `isctype` Values returned from `lookup_classname` can be bitwise or'ed together; the resulting value represents membership in either of the corresponding character classes If `b` is true, the returned bitmask is suitable for matching characters without regard to their case. Returns `0` if the character sequence is not the name of a character class recognized by `X`. The value returned shall be independent of the case of the characters in the sequence.
`v.isctype(c, cl)`	`bool`	Returns: whether `c` is a member of one of the character classes designated by `cl` or not.
`v.value(c, I)`	`int`	Returns: The value represented by the digit `c` in base `I` if the character `c` is a valid digit in base `I` `-1` otherwise
`u.imbue(loc)`	`X::locale_type`	Imbues `u` with the locale `loc` Returns: The previous locale used by `u` if any
`v.getloc()`	`X::locale_type`	Returns: The previous locale used by `v` if any.

Standard library

RegexTraits is satisfied by the following standard library classes:

template<> class regex_traits<char>;
template<> class regex_traits<wchar_t>;

(since C++11)
(since C++11)

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