std::char_traits<CharT>::find

From cppreference.com
< cpp‎ | string‎ | char traits
static const char_type* find( const char_type* p, std::size_t count, const char_type& ch );
(until C++17)
static constexpr const char_type* find( const char_type* p, std::size_t count, const char_type& ch );
(since C++17)

Searches for character ch within the first count characters of the sequence pointed to by p.

Parameters

p - pointer to a character string to search
count - the number of characters to analyze
ch - the character to search for

Return value

A pointer to the first character in the range specified by [p, p + count) that compares equal to ch, or a null pointer if not found.

Exceptions

Throws nothing.

Complexity

Linear in count.