std::literals::string_view_literals::operator""sv

 

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basic_string

basic_string_view (C++17)

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std::basic_string_view

Member functions basic_string_view::basic_string_view    basic_string_view::operator= Iterators basic_string_view::beginbasic_string_view::cbegin basic_string_view::endbasic_string_view::cend basic_string_view::rbeginbasic_string_view::crbegin basic_string_view::rendbasic_string_view::crend Element access basic_string_view::at basic_string_view::operator[] basic_string_view::front basic_string_view::back basic_string_view::data Capacity basic_string_view::sizebasic_string_view::length basic_string_view::max_size basic_string_view::empty Modifiers basic_string_view::remove_prefix basic_string_view::remove_suffix basic_string_view::swap

Operations basic_string_view::copy basic_string_view::substr basic_string_view::compare basic_string_view::starts_with (C++20) basic_string_view::ends_with (C++20) basic_string_view::contains (C++23) basic_string_view::find basic_string_view::rfind basic_string_view::find_first_of basic_string_view::find_last_of basic_string_view::find_first_not_of basic_string_view::find_last_not_of Constants basic_string_view::npos Non-member functions operator==operator!=operator<operator>operator<=operator>=operator<=> (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)(C++20) operator<< operator""sv Helper classes hash<std::string_view>hash<std::wstring_view>hash<std::u8string_view>hash<std::u16string_view>hash<std::u32string_view> (C++20) Deduction guides(C++20)

 

Defined in header <string_view>
constexpr std::string_view     operator ""sv( const char* str, std::size_t len ) noexcept;	(1)	(since C++17)
constexpr std::u8string_view     operator ""sv( const char8_t* str, std::size_t len ) noexcept;	(2)	(since C++20)
constexpr std::u16string_view     operator ""sv( const char16_t* str, std::size_t len ) noexcept;	(3)	(since C++17)
constexpr std::u32string_view     operator ""sv( const char32_t* str, std::size_t len ) noexcept;	(4)	(since C++17)
constexpr std::wstring_view     operator ""sv( const wchar_t* str, std::size_t len ) noexcept;	(5)	(since C++17)

Forms a string view of a character literal.

1) Returns std::string_view{str, len}.

2) Returns std::u8string_view{str, len}.

3) Returns std::u16string_view{str, len}.

4) Returns std::u32string_view{str, len}.

5) Returns std::wstring_view{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 std::basic_string_view literal.

Notes

These operators are declared in the namespace std::literals::string_view_literals, where both literals and string_view_literals are inline namespaces. Access to these operators can be gained with any of:

• using namespace std::literals,
• using namespace std::string_view_literals, or
• using namespace std::literals::string_view_literals.

Example

Run this code

#include <iostream>
#include <string_view>
#include <typeinfo>
 
void print_each_character(const std::string_view sw)
{
    for (char c : sw)
        std::cout << (c == '\0' ? '@' : c);
    std::cout << '\n';
}
 
int main()
{
    using namespace std::literals;
 
    std::string_view s1 = "abc\0\0def";
    std::string_view s2 = "abc\0\0def"sv;
 
    std::cout << "s1.size(): " << s1.size() << "; s1: ";
    print_each_character(s1);
    std::cout << "s2.size(): " << s2.size() << "; s2: ";
    print_each_character(s2);
 
    std::cout << "substr(1, 4): " << "abcdef"sv.substr(1, 4) << '\n';
 
    auto value_type_info = []<typename T>(T)
    {
        using V = typename T::value_type;
        std::cout << "sizeof " << typeid(V).name() << ": " << sizeof(V) << '\n';
    };
 
    value_type_info("char A"sv);
    value_type_info(L"wchar_t ∀"sv);
    value_type_info(u8"char8_t ∆"sv);
    value_type_info(u"char16_t ∇"sv);
    value_type_info(U"char32_t ∃"sv);
    value_type_info(LR"(raw ⊞)"sv);
}

Possible output:

s1.size(): 3; s1: abc
s2.size(): 8; s2: abc@@def
substr(1, 4): bcde
sizeof char: 1
sizeof wchar_t: 4
sizeof char8_t: 1
sizeof char16_t: 2
sizeof char32_t: 4
sizeof wchar_t: 4

See also

(constructor)	constructs a basic_string_view (public member function)
operator""s (C++14)	converts a character array literal to basic_string (function)