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constexpr basic_string_view substr( size_type pos=0, size_type count= npos)const; | (since C++17) | |
Returns a view of the substring[pos, pos+ rlen), whererlen is the smaller ofcount andsize()- pos.
Contents |
| pos | - | position of the first character |
| count | - | requested length |
View of the substring[pos, pos+ rlen).
std::out_of_range ifpos> size().
Constant.
#include <cstddef>#include <iostream>#include <stdexcept>#include <string_view> int main(){typedefstd::size_t count_t, pos_t; constexprstd::string_view data{"ABCDEF"}; std::cout<< data.substr()<<'\n';// ABCDEF, i.e. data[0, 5] that is [0, 6)std::cout<< data.substr(pos_t(1))<<'\n';// BCDEF, i.e. [1, 6)std::cout<< data.substr(pos_t(2), count_t(3))<<'\n';// CDE, i.e. [2, 2 + 3)std::cout<< data.substr(pos_t(4), count_t(42))<<'\n';// EF, i.e. [4, 6) try{[[maybe_unused]]auto sub= data.substr(pos_t(666), count_t(1));// throws: pos > size()}catch(std::out_of_rangeconst& ex){std::cout<< ex.what()<<'\n';}}
Possible output:
ABCDEFBCDEFCDEEFbasic_string_view::substr: __pos (which is 666) > __size (which is 6)
| copies characters (public member function)[edit] | |
| find characters in the view (public member function)[edit] | |
| returns a substring (public member function of std::basic_string<CharT,Traits,Allocator>)[edit] |
