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constexpr size_type find_first_of( basic_string_view v, size_type pos=0)constnoexcept; | (1) | (since C++17) |
constexpr size_type find_first_of( CharT ch, size_type pos=0)constnoexcept; | (2) | (since C++17) |
constexpr size_type find_first_of(const CharT* s, size_type pos, size_type count)const; | (3) | (since C++17) |
constexpr size_type find_first_of(const CharT* s, size_type pos=0)const; | (4) | (since C++17) |
Finds the first character equal to any of the characters in the given character sequence.
Contents |
| v | - | view to search for |
| pos | - | position at which to start the search |
| count | - | length of the string of characters to search for |
| s | - | pointer to a string of characters to search for |
| ch | - | character to search for |
Position of the first occurrence of any character of the substring, ornpos if no such character is found.
O(size() * v.size()) at worst.
#include <string_view> usingnamespace std::literals;constexprauto N=std::string_view::npos; constexprbool is_white_space(constchar c){return"\t\n\f\r\v"sv.find_first_of(c)!= N;}; static_assert(1=="alignas"sv.find_first_of("klmn"sv)&&// └─────────────────────────┘ N=="alignof"sv.find_first_of("wxyz"sv)&&//3=="concept"sv.find_first_of("bcde"sv,/* pos= */1)&&// └───────────────────────┘ N=="consteval"sv.find_first_of("oxyz"sv,/* pos= */2)&&//6=="constexpr"sv.find_first_of('x')&&// └─────────────────────┘ N=="constinit"sv.find_first_of('x')&&//6=="const_cast"sv.find_first_of('c',/* pos= */4)&&// └──────────────────────┘ N=="continue"sv.find_first_of('c',/* pos= */42)&&//5=="co_await"sv.find_first_of("cba",/* pos= */4)&&// └───────────────────────┘7=="decltype"sv.find_first_of("def",/* pos= */2,/* count= */2)&&// └────────────────────┘ N=="decltype"sv.find_first_of("def",/* pos= */2,/* count= */1)&&// is_white_space(' ')&& is_white_space('\r')&&!is_white_space('\a')); int main(){}
| find characters in the view (public member function)[edit] | |
| find the last occurrence of a substring (public member function)[edit] | |
| find last occurrence of characters (public member function)[edit] | |
| find first absence of characters (public member function)[edit] | |
| find last absence of characters (public member function)[edit] | |
| find first occurrence of characters (public member function of std::basic_string<CharT,Traits,Allocator>)[edit] |
