From cppreference.com
constexprsize_typesize()constnoexcept;(since C++17)constexprsize_typelength()constnoexcept;(since C++17)Returns the number of CharT elements in the view, i.e. std::distance(begin(),end()).
Return value
The number of CharT elements in the view.
Complexity
Constant.
Example
Run this code
#include<iostream>#include<string_view>// Print a string surrounded by single quotes, its// length and whether it is considered empty.voidcheck_string(std::string_viewref){std::cout<<std::boolalpha<<"'"<<ref<<"' has "<<ref.size()<<" character(s); emptiness: "<<ref.empty()<<'\n';}intmain(intargc,char**argv){// An empty stringcheck_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
checks whether the view is empty
(public member function)
returns the maximum number of characters
(public member function)
returns the number of characters
(public member function of std::basic_string<CharT,Traits,Allocator>)