static_string

A C++11 single-header library for representing and concatenating constexpr string literals.

Usage

You use this library if you want to build a relatively short string whose contents you know at compile time, and you want to make sure no static initialization order fiasco ever occurs.

#include <iostream>
#include "static_string.hpp"
namespace sstr = ak_toolkit::static_str;

constexpr auto SERVICE_NAME = sstr::literal("SRVC1");
// SERVICE_NAME has type sstr::string_literal<5>
// string_literal is a reference to a C-like string literal, but with different interface
// length of the literal is part of the type

constexpr auto MESSAGE = "service " + SERVICE_NAME + " ready";
// MESSAGE has type sstr::array_string<8 + 5 + 6>
// array_string is an array that stores the null-terminated literal
// length of the array (excluding the trailing zero) is part of the type

int main()
{
  std::cout << MESSAGE << std::endl;
  // outputs: "service SRVC1 ready"

  const char * msg = MESSAGE; // conversion to const char *
  std::cout << msg << std::endl;
  // outputs: "service SRVC1 ready"
}

You can also take a part of a string literal starting at a given offset:

constexpr auto FILENAME = sstr::offset_literal<4>("dir/filename");
// FILENAME has type sstr::array_string<8>

int test()
{
  std::cout << FILENAME << std::endl;
  // outputs: "filename"
}

Or:

constexpr auto fpath = sstr::literal("path/fname");
constexpr auto fname = sstr::suffix(fpath, 5);
// decltype(fname) is sstr::string_literal_suffix<10>
// fname.size() == 5

constexpr auto full_fname = fname + ".txt";
// decltype(fname) is sstr::array_string_suffix<10 + 4>
// fname.size() == 9

  std::cout << full_fname << std::endl;
  // outputs: "fname.txt"

For more information see this blog post.

Installation

It is a C++11 header-only library.

Configuration

If you define macro AK_TOOLKIT_CONFIG_USING_STRING_VIEW as 1, 2, 3, or 4 prior to including header ak_toolkit/static_string.hpp then the library will also provide conversion operator to type string_view, where the type of string_view is defined depending on the value of macro AK_TOOLKIT_CONFIG_USING_STRING_VIEW as follows:

• 1: std::string_view
• 2: std::experimental::string_view
• 3: boost::string_ref
• 4: std::string

If you define macro AK_TOOLKIT_CONFIG_USING_STRING prior to including header ak_toolkit/static_string.hpp then the library will additionally provide two overloads of operator+ taking string_view on one side and and any of the static strings on the other.

License

Distributed under the Boost Software License, Version 1.0.