NAME¶

std::basic_string_view::find - std::basic_string_view::find

Synopsis¶

constexpr size_type find( basic_string_view v, size_type pos = 0 ) (1) (since C++17)
const noexcept;
constexpr size_type find( CharT ch, size_type pos = 0 ) const (2) (since C++17)
noexcept;
constexpr size_type find( const CharT* s, size_type pos, size_type (3) (since C++17)
count ) const;
constexpr size_type find( const CharT* s, size_type pos = 0 ) (4) (since C++17)
const;

Finds the first substring equal to the given character sequence.

1) Finds the first occurence of v in this view, starting at position pos.
2) Equivalent to find(basic_string_view(std::addressof(ch), 1), pos).
3) Equivalent to find(basic_string_view(s, count), pos).
4) Equivalent to find(basic_string_view(s), pos).

Parameters¶

v - view to search for
pos - position at which to start the search
count - length of substring to search for
s - pointer to a character string to search for
ch - character to search for

Return value¶

Position of the first character of the found substring, or npos if no such substring
is found.

Complexity¶

O(size() * v.size()) at worst.

Example¶

// Run this code

#include <string_view>

int main()
{
using namespace std::literals;

constexpr auto str{" long long int;"sv};

static_assert(
1 == str.find("long"sv) && "<- find(v , pos = 0)" &&
6 == str.find("long"sv, 2) && "<- find(v , pos = 2)" &&
0 == str.find(' ') && "<- find(ch, pos = 0)" &&
2 == str.find('o', 1) && "<- find(ch, pos = 1)" &&
2 == str.find("on") && "<- find(s , pos = 0)" &&
6 == str.find("long double", 5, 4) && "<- find(s , pos = 5, count = 4)"
);

static_assert(str.npos == str.find("float"));
}

See also¶

rfind find the last occurrence of a substring
(C++17) (public member function)
find_first_of find first occurrence of characters
(C++17) (public member function)
find_last_of find last occurrence of characters
(C++17) (public member function)
find_first_not_of find first absence of characters
(C++17) (public member function)
find_last_not_of find last absence of characters
(C++17) (public member function)
find characters in the string
find (public member function of
std::basic_string<CharT,Traits,Allocator>)