From cppreference.com
constexprstd::basic_string_view<CharT,Traits>subview(size_typepos=0,size_typecount=npos)const;(since C++26)Returns a view of the substring [pos, pos+rlen), where rlen is the smaller of count and size()-pos.
Equivalent to returnstd::basic_string_view<CharT,Traits>(*this).subview(pos,count);.
Parameters
pos - position of the first character to include count - length of the sub-view Return value
View of the substring [pos, pos+rlen).
Exceptions
if pos>size().
Complexity
Constant.
Notes
macro ValueStdFeature
(C++26)std::basic_string::subview, std::basic_string_view::subviewExample
Run this code
#include<cassert>#include<iostream>#include<string>#include<string_view>intmain(){conststd::strings{"Life is life!"};assert(s.subview(5)=="is life!");assert(s.subview(5,13)=="is life!");assert(s.subview(5,2)=="is");try{// pos is out of bounds, throwsconstautopos{s.length()+13};[[maybe_unused]]autox_x{s.subview(pos)};}catch(conststd::out_of_range&ex){std::cout<<"Exception: "<<ex.what()<<'\n';}}Possible output:
Exception: basic_string_view::substr: __pos (which is 26) > __size (which is 13) See also
returns a substring
(public member function)
(C++26)
returns a sub-view
(public member function of std::basic_string_view<CharT,Traits>)