Single-header version requires two files to be included

[tocic]

Single-header version requires two files to be included

[lemire]

From the README:

You can create a single-header version of the library where all of the code is put into two files (simdutf.h and simdutf.cpp). We publish a zip archive containing these files, e.g., see https://github.com/simdutf/simdutf/releases/download/v3.2.2/singleheader.zip

There is a single header and a single source file.

We provide an example... here is a simplified version:

#include <iostream>
#include <memory>

#include "simdutf.cpp"
#include "simdutf.h"

int main(int , char *[]) {
  const char *source = "1234";
  // 4 == strlen(source)
  bool validutf8 = simdutf::validate_utf8(source, 4);
  if (validutf8) {
    std::cout << "valid UTF-8" << std::endl;
  } else {
    std::cerr << "invalid UTF-8" << std::endl;
    return EXIT_FAILURE;
  }
  return EXIT_SUCCESS;
}

Also, I expect to be able to install both versions at the same time. But now the amalgamated file from the zip archive and include/simduft.h have the same name, so it's unclear how to differentiate them in CMAKE_INSTALL_INCLUDEDIR.

I am not sure what you mean by both at the same time. You can either use the single-header version, in which case you just copy simdutf.h and simdutf.cpp to your project. Or else, if you want to use simdutf as an installed package of some sort, then you do so... Here is a CMake example...

cmake_minimum_required(VERSION 3.15)

project(test_simdutf_install VERSION 0.1.0 LANGUAGES CXX)

set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
if(MSVC_VERSION GREATER 1910)
  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -permissive-")
endif()
find_package(simdutf REQUIRED)



file(WRITE main.cpp "
#include <iostream>
#include \"simdutf.h\"
int main(int argc, char *argv[]) {
   const char * ascii = \"1234\";
   bool validutf8 = simdutf::validate_utf8(ascii, 4);
   if(validutf8) {
       std::cout << \"valid UTF-8\" << std::endl;
   } else {
       std::cout << \"invalid UTF-8\" << std::endl;
       return EXIT_FAILURE;
   }
   char16_t utf16_output[4];
   // convert to UTF-16LE
   size_t utf16words = simdutf::convert_utf8_to_utf16le(ascii, 4, utf16_output);
   std::cout << \"wrote \" << utf16words << \" UTF-16 words.\" << std::endl;
   // It wrote utf16words * sizeof(char16_t) bytes.
   //
   // convert it back:
   char buffer[4];
   size_t utf8words = simdutf::convert_utf16le_to_utf8(utf16_output, utf16words, buffer);
   std::cout << \"wrote \" << utf8words << \" UTF-8 words.\" << std::endl;
   return EXIT_SUCCESS;
}")



add_executable(repro main.cpp)
target_link_libraries(repro PUBLIC simdutf::simdutf)

[lemire]

If you use the single-header release, then two files must be installed the header (there is just one) and the source file.

[lemire]

From CMake, you can use simdutf as a dependency as follows...

cmake_minimum_required(VERSION 3.15)

project(simdutf_demo_install VERSION 0.1.0 LANGUAGES CXX)


set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
include(FetchContent)

FetchContent_Declare(
  simdutf
  GIT_REPOSITORY [email protected]:simdutf/simdutf.git
  GIT_SHALLOW TRUE
  GIT_TAG tags/v3.2.2
  )
FetchContent_MakeAvailable(simdutf)

file(WRITE main.cpp "
#include <iostream>
#include \"simdutf.h\"
int main(int argc, char *argv[]) {
   const char * ascii = \"1234\";
   bool validutf8 = simdutf::validate_utf8(ascii, 4);
   if(validutf8) {
       std::cout << \"valid UTF-8\" << std::endl;
   } else {
       std::cout << \"invalid UTF-8\" << std::endl;
       return EXIT_FAILURE;
   }
   char16_t utf16_output[4];
   // convert to UTF-16LE
   size_t utf16words = simdutf::convert_utf8_to_utf16le(ascii, 4, utf16_output);
   std::cout << \"wrote \" << utf16words << \" UTF-16 words.\" << std::endl;
   // It wrote utf16words * sizeof(char16_t) bytes.
   //
   // convert it back:
   char buffer[4];
   size_t utf8words = simdutf::convert_utf16le_to_utf8(utf16_output, utf16words, buffer);
   std::cout << \"wrote \" << utf8words << \" UTF-8 words.\" << std::endl;
   return EXIT_SUCCESS;
}")



add_executable(repro main.cpp)
target_link_libraries(repro PUBLIC simdutf::simdutf)

[lemire]

I am going to close the issue. The reporter is correct, they need two files for the single-header version.

[lemire]

As a last remark: we do not and probably never will support having both the single-header and another version of the simdutf library in the same project. It is the same code, same library, just packaged differently. Many users find the single-header version simpler.

[tocic]

If you use the single-header release, then two files must be installed the header (there is just one) and the source file.

I understand, but I expected "single-header" to be "header-only". And I've never seen the inclusion of a .cpp file in other projects. You are free to use any distribution method you want, of course, just wanted to know your motivation for this.

I am not sure what you mean by both at the same time

I meant simultaneous installation, not usage. So you can package both versions of the library and give users a chance to select the version they want. Currently, IIUC, you need to create 2 different packages or manually rename/move files.

[lemire]

If you believe that there is a shortcoming, please consider providing a pull request.