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std::literals::string_literals::operator""s

Defined in header `<string>`
	(1)
std::string operator""s( const char *str, std::size_t len );		(since C++14) (until C++20)
constexpr std::string operator""s( const char *str, std::size_t len );		(since C++20)
constexpr std::u8string operator""s( const char8_t *str, std::size_t len );	(2)	(since C++20)
	(3)
std::u16string operator""s( const char16_t *str, std::size_t len );		(since C++14) (until C++20)
constexpr std::u16string operator""s( const char16_t *str, std::size_t len );		(since C++20)
	(4)
std::u32string operator""s( const char32_t *str, std::size_t len );		(since C++14) (until C++20)
constexpr std::u32string operator""s( const char32_t *str, std::size_t len );		(since C++20)
	(5)
std::wstring operator""s( const wchar_t *str, std::size_t len );		(since C++14) (until C++20)
constexpr std::wstring operator""s( const wchar_t *str, std::size_t len );		(since C++20)

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 either

using namespace std::literals, or
using namespace std::string_literals, or
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.

Feature-test macro	Value	Std	Comment
`__cpp_lib_string_udls`	201304L	(C++14)	User-defined literals for string types

Example

#include <iostream>
#include <string>
 
void print_with_zeros(auto const note, std::string const& s)
{
    std::cout << note;
    for (const char c : s)
        c ? std::cout << c : std::cout << "₀";
    std::cout << " (size = " << s.size() << ")\n";
}
 
int main()
{
    using namespace std::string_literals;
 
    std::string s1 = "abc\0\0def";
    std::string s2 = "abc\0\0def"s;
    print_with_zeros("s1: ", s1);
    print_with_zeros("s2: ", s2);
 
    std::cout << "abcdef"s.substr(1,4) << '\n';
}

Output:

s1: abc (size = 3)
s2: abc₀₀def (size = 8)
bcde

(constructor)	constructs a `basic_string` (public member function)
operator""sv (C++17)	creates a string view of a character array literal (function)

std::literals::string_literals::operator""s

Parameters

Return value

Notes

Example

See also