std::literals::string_literals::operator""s
From cppreference.com
< cpp | string | basic string
Defined in header <string>
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string operator "" s(const char *str, std::size_t len); |
(1) | (since C++14) |
u8string operator "" s(const char8_t *str, std::size_t len); |
(2) | (since C++20) |
u16string operator "" s(const char16_t *str, std::size_t len); |
(3) | (since C++14) |
u32string operator "" s(const char32_t *str, std::size_t len); |
(4) | (since C++14) |
wstring operator "" s(const wchar_t *str, std::size_t len); |
(5) | (since C++14) |
Forms a string literal of the desired type.
1) returns std::string{str, len}
2) returns std::u8string{str, len}
3) returns std::u16string{str, len}
4) returns std::u32string{str, len}
5) returns std::wstring{str, len}
Parameters
str | - | pointer to the beginning of the raw character array literal |
len | - | length of the raw character array literal |
Return value
The string literal.
Notes
These operators are declared in the namespace std::literals::string_literals
, where both literals
and string_literals
are inline namespaces. Access to these operators can be gained with using namespace std::literals, using namespace std::string_literals, and using namespace std::literals::string_literals.
std::chrono::duration also defines operator""s
, to represent literal seconds, but it is an arithmetic literal: 10.0s and 10s are ten seconds, but "10"s is a string.
Example
Run this code
#include <string> #include <iostream> int main() { using namespace std::string_literals; std::string s1 = "abc\0\0def"; std::string s2 = "abc\0\0def"s; std::cout << "s1: " << s1.size() << " \"" << s1 << "\"\n"; std::cout << "s2: " << s2.size() << " \"" << s2 << "\"\n"; }
Possible output:
s1: 3 "abc" s2: 8 "abc^@^@def"
See also
constructs a basic_string (public member function) |