NAME¶

std::basic_string_view::size,std::basic_string_view::length - std::basic_string_view::size,std::basic_string_view::length

Synopsis¶

constexpr size_type size() const noexcept; (since C++17)
constexpr size_type length() const noexcept; (since C++17)

Returns the number of CharT elements in the view, i.e. std::distance(begin(),
end()).

Parameters¶

(none)

Return value¶

The number of CharT elements in the view.

Complexity¶

Constant.

Example¶

// Run this code

#include <string_view>
#include <iostream>

void check_string(std::string_view ref)
{
// Print a string surrounded by single quotes, its length
// and whether it is considered empty.
std::cout << std::boolalpha
<< "'" << ref << "' has " << ref.size()
<< " character(s); emptiness: " << ref.empty() << '\n';
}

int main(int argc, char **argv)
{
// An empty string
check_string("");

// Almost always not empty: argv[0]
if (argc > 0)
check_string(argv[0]);
}

Possible output:¶

'' has 0 character(s); emptiness: true
'./a.out' has 7 character(s); emptiness: false

See also¶

empty checks whether the view is empty
(C++17) (public member function)
max_size returns the maximum number of characters
(C++17) (public member function)
size returns the number of characters
length (public member function of std::basic_string<CharT,Traits,Allocator>)