std::basic_string_view<CharT,Traits>::size, std::basic_string_view<CharT,Traits>::length
Min standard notice:
Returns the number of CharT elements in the view, i.e. std::distance(begin(), end()).
# Declarations
constexpr size_type size() const noexcept;
(since C++17)
constexpr size_type length() const noexcept;
(since C++17)
# Return value
The number of CharT elements in the view.
# Example
#include <iostream>
#include <string_view>
// Print a string surrounded by single quotes, its
// length and whether it is considered empty.
void check_string(std::string_view ref)
{
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]);
}