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std::basic_string_view<CharT,Traits>::size, std::basic_string_view<CharT,Traits>::length

From cppreference.com
 
 
 
 
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()).

Contents

[edit] Parameters

(none)

[edit] Return value

The number of CharT elements in the view.

[edit] Complexity

Constant.

[edit] Example

#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

[edit] See also

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