operators (std::basic_string)

Compare two `basic_string` objects
template< class CharT, class Traits, class Alloc > bool operator==( const basic_string<CharT,Traits,Alloc>& lhs, const basic_string<CharT,Traits,Alloc>& rhs );	(1)
template< class CharT, class Traits, class Alloc > bool operator!=( const basic_string<CharT,Traits,Alloc>& lhs, const basic_string<CharT,Traits,Alloc>& rhs );	(2)
template< class CharT, class Traits, class Alloc > bool operator<( const basic_string<CharT,Traits,Alloc>& lhs, const basic_string<CharT,Traits,Alloc>& rhs );	(3)
template< class CharT, class Traits, class Alloc > bool operator<=( const basic_string<CharT,Traits,Alloc>& lhs, const basic_string<CharT,Traits,Alloc>& rhs );	(4)
template< class CharT, class Traits, class Alloc > bool operator>( const basic_string<CharT,Traits,Alloc>& lhs, const basic_string<CharT,Traits,Alloc>& rhs );	(5)
template< class CharT, class Traits, class Alloc > bool operator>=( const basic_string<CharT,Traits,Alloc>& lhs, const basic_string<CharT,Traits,Alloc>& rhs );	(6)
Compare a `basic_string` object and null-terminated array of `T`
template< class CharT, class Traits, class Alloc > bool operator==( const CharT* lhs, const basic_string<CharT,Traits,Alloc>& rhs );	(7)
template< class CharT, class Traits, class Alloc > bool operator==( const basic_string<CharT,Traits,Alloc>& lhs, const CharT* rhs );	(7)
template< class CharT, class Traits, class Alloc > bool operator!=( const CharT* lhs, const basic_string<CharT,Traits,Alloc>& rhs );	(8)
template< class CharT, class Traits, class Alloc > bool operator!=( const basic_string<CharT,Traits,Alloc>& lhs, const CharT* rhs );	(8)
template< class CharT, class Traits, class Alloc > bool operator<( const CharT* lhs, const basic_string<CharT,Traits,Alloc>& rhs );	(9)
template< class CharT, class Traits, class Alloc > bool operator<( const basic_string<CharT,Traits,Alloc>& lhs, const CharT* rhs );	(9)
template< class CharT, class Traits, class Alloc > bool operator<=( const CharT* lhs, const basic_string<CharT,Traits,Alloc>& rhs );	(10)
template< class CharT, class Traits, class Alloc > bool operator<=( const basic_string<CharT,Traits,Alloc>& lhs, const CharT* rhs );	(10)
template< class CharT, class Traits, class Alloc > bool operator>( const CharT* lhs, const basic_string<CharT,Traits,Alloc>& rhs );	(11)
template< class CharT, class Traits, class Alloc > bool operator>( const basic_string<CharT,Traits,Alloc>& lhs, const CharT* rhs );	(11)
template< class CharT, class Traits, class Alloc > bool operator>=( const CharT* lhs, const basic_string<CharT,Traits,Alloc>& rhs );	(12)
template< class CharT, class Traits, class Alloc > bool operator>=( const basic_string<CharT,Traits,Alloc>& lhs, const CharT* rhs );	(12)

Compares the contents of a string with another string or a null-terminated array of CharT.

All comparisons are done via the compare() member function (which itself is defined in terms of Traits::compare()):

Two strings are equal if both the size of lhs and rhs are equal and each character in lhs has equivalent character in rhs at the same position.
The ordering comparisons are done lexicographically -- the comparison is performed by a function equivalent to std::lexicographical_compare.

1-6) Compares two basic_string objects.

7-12) Compares a basic_string object and a null-terminated array of CharT.

Parameters

lhs, rhs

strings whose contents to compare

Return value

true if the corresponding comparison holds, false otherwise.

Exceptions

1-6)

(none)	(until C++14)
`noexcept` specification: `noexcept`	(since C++14)

7-12) (none)

Complexity

Linear in the size of the strings.

Links:

http://en.cppreference.com/w/cpp/string/basic_string/operator_cmp

doc_CPP

2016-10-11 09:59:30

Comments