for_each.hpp File Reference

#include "details/for_each_impl.hpp"

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Functions
template<typename... ARGS>
constexpr void	bsl::for_each (ARGS &&... args) noexcept(noexcept(//-- details::for_each_impl< ARGS... >::call(bsl::forward< ARGS >(args)...)))
	Loops over a view or a pair of iterators, calling a provided function on each iteration. The provided function can take on the following signatures: More...

Variables
constexpr bool	bsl::for_each_break {false}
	Tells a foreach to stop its execution (same as "break")
constexpr bool	bsl::for_each_continue {true}
	Tells a foreach to continue its execution (same as "continue")

Detailed Description

Copyright

Copyright (C) 2020 Assured Information Security, Inc.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Function Documentation

for_each()

template<typename... ARGS>

constexpr void bsl::for_each ( ARGS &&...  args )

noexcept

Loops over a view or a pair of iterators, calling a provided function on each iteration. The provided function can take on the following signatures:

• void(T &elem)
• void(T &elem, bsl::uintmax index)
• bool(T &elem)
• bool(T &elem, bsl::uintmax index) The boolean versions of this function allow you to return either bsl::for_each_break (to break from the loop) or for_each_continue (to continue the loop). Note that if you are using the void versions of the loop, you can continue by simply returning. The bool versions are only needed if you need to break from the loop, in which case bsl::for_each_continue should be used to return from the function. In addition to the different function signatures that you can provide, you can also provide bsl::for_each with either a subclass of a bsl::view, or two iterators (a begin and end iterator), which will be used to perform the loop. The bsl::for_each function acts like a ranged for loop when given a subclass of a bsl::view, and acts like a traditional for loop when given two iterators. Note that you can use a reverse iterator to loop in reverse, and you can use the BSL specific iter() functions that allow you to create your own begin and end iterators so that you can control the position and number of elements the loop will perform. For more information, see the following example:

  
  #include <bsl/for_each.hpp>
  #include <bsl/string_view.hpp>
  #include <bsl/debug.hpp>
  
  namespace bsl
  {
      inline void
      example_for_each_overview() noexcept
      {
          constexpr bsl::string_view msg{"Hello"};
          constexpr bsl::uintmax i1{1U};
          constexpr bsl::uintmax i4{4U};
          constexpr char_type co{'o'};
  
          // ---------------------------------------------------------------------
          bsl::print() << "example 1:\n";
          bsl::for_each(msg, [](auto &e) noexcept {
              bsl::print() << e;
          });
          bsl::print() << "\n\n";
  
          // ---------------------------------------------------------------------
          bsl::print() << "example 2:\n";
          bsl::for_each(msg, [](auto &e, auto const i) noexcept {
              bsl::print() << "element [" << i << "] == " << e << bsl::endl;
          });
          bsl::print() << bsl::endl;
  
          // ---------------------------------------------------------------------
          bsl::print() << "example 3:\n";
          bsl::for_each(msg, [](auto &e) noexcept -> bool {
              if (co == e) {
                  return bsl::for_each_break;
              }
  
              bsl::print() << e;
              return for_each_continue;
          });
          bsl::print() << "\n\n";
  
          // ---------------------------------------------------------------------
          bsl::print() << "example 4:\n";
          bsl::for_each(msg.begin(), msg.end(), [](auto &e) noexcept {
              bsl::print() << e;
          });
          bsl::print() << "\n\n";
  
          // ---------------------------------------------------------------------
          bsl::print() << "example 5:\n";
          bsl::for_each(msg.iter(i1), msg.iter(i4), [](auto &e) noexcept {
              bsl::print() << e;
          });
          bsl::print() << "\n\n";
  
          // ---------------------------------------------------------------------
          bsl::print() << "example 6:\n";
          bsl::for_each(msg.rbegin(), msg.rend(), [](auto &e) noexcept {
              bsl::print() << e;
          });
          bsl::print() << "\n\n";
  
          // ---------------------------------------------------------------------
          bsl::print() << "example 7:\n";
          bsl::for_each(msg.rbegin(), msg.rend(), [](auto &e, auto const i) noexcept {
              bsl::print() << "element [" << i << "] == " << e << bsl::endl;
          });
      }
  }

Template Parameters

ARGS	the types of arguments passed to bsl::for_each.

Parameters

args	can either be a subclass of bsl::view and a lambda, or a pair of iterators and a lambda.