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std::basic_...emove_prefix(3)  C++ Standard Libary std::basic_...emove_prefix(3)

NAME
     std::basic_string_view::remove_prefix - std::basic_string_view::remove_pre-
     fix

Synopsis
	constexpr void remove_prefix( size_type n );  (since C++17)

	Moves the start of the view forward by n characters.

	The behavior is undefined if n > size().

Parameters
	n - number of characters to remove from the start of the view

Return value
	(none)

Complexity
	Constant.

Example
     // Run this code

      #include <algorithm>
      #include <iostream>
      #include <string_view>

      using namespace std::literals;

      [[nodiscard("a pure function")]]
      constexpr      std::size_t     count_substrings(std::string_view	   hive,
     std::string_view const bee)
      {
	  if (hive.empty() || bee.empty())
	      return 0U;

	  std::size_t buzz{};
	  while (bee.size() <= hive.size())
	  {
	      const auto pos = hive.find(bee);
	      if (pos == hive.npos)
		  break;
	      ++buzz;
	      hive.remove_prefix(pos + bee.size());
	  }
	  return buzz;
      }

      int main()
      {
	  std::string str = "	trim me";
	  std::string_view v = str;
	  v.remove_prefix(std::min(v.find_first_not_of(" "), v.size()));
	  std::cout << "String: '" << str << "'\n"
		    << "View  : '" << v << "'\n";

	  constexpr auto hive{"bee buzz bee buzz bee"};
	  std::cout << "There are " << count_substrings(hive, "bee") <<  "  bees
     in this hive.\n";
      }

Output:
      String: '   trim me'
      View  : 'trim me'
      There are 3 bees in this hive.

See also
	remove_suffix shrinks the view by moving its end backward
		      (public member function)

http://cppreference.com 	   2024.06.10	   std::basic_...emove_prefix(3)
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