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      std::basic_string_view<CharT,Traits>::operator[]

      From cppreference.com
      <cpp‎ |string‎ |basic string view
       
       
       
      std::basic_string_view
       
      constexpr const_reference operator[]( size_type pos)const;
      (since C++17)

      Returns a const reference to the character at specified locationpos.

      Ifpos< size() isfalse, the behavior is undefined.

      (until C++26)

      Ifpos< size() isfalse:

      • If the implementation ishardened, acontract violation occurs. Moreover, if the contract-violation handler returns under “observe” evaluation semantic, the behavior is undefined.
      • If the implementation is not hardened, the behavior is undefined.
      (since C++26)

      Contents

      [edit]Parameters

      pos - position of the character to return

      [edit]Return value

      data_ [pos]

      [edit]Exceptions

      Does not throw.

      [edit]Complexity

      Constant.

      [edit]Notes

      Unlikestd::basic_string::operator[],std::basic_string_view::operator[](size()) does not return a reference toCharT().

      [edit]Example

      Run this code
      #include <iostream>#include <string_view> int main(){std::string str="Exemplar";std::string_view v= str;std::cout<< v[2]<<'\n';//  v[2] = 'y'; // Error: cannot modify through a string view    str[2]='y';std::cout<< v[2]<<'\n';}

      Output:

      ey

      [edit]See also

      accesses the specified character with bounds checking
      (public member function)[edit]
      accesses the specified character
      (public member function ofstd::basic_string<CharT,Traits,Allocator>)[edit]
      Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/string/basic_string_view/operator_at&oldid=182306"

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