CODEWITHSUNDEEP
c++qtsmart-pointersninjameson-build
Bebel
Bebel

Reputation: 49

How to properly configure meson / ninja / qt creator for recent c++ version?

I have tried to run a code which uses smart pointers recently. As the title says, I use Ninja (version 1.10.2), Meson (0.57.2) and Qt Creator 4.14.2. I have the following meson.build :

project('RayTracerDemo',
    'cpp',
    version: '0.0.0',
    default_options: [
        'c_std=c2x',
        'cpp_std=c++20',
        'warning_level=3',
        'optimization=3',
        'werror=true'
    ]
)

includeDir = include_directories([])

sources = files([
    'main.cpp'
])

headers = files([])

raytracer_exe = executable(
    'RayTracerDemo',
    sources: sources + headers,
    include_directories: includeDir,
    dependencies: []
)

But I still get the following error :

/~/programs/RayTracerDemo/main.cpp:189: error: ‘make_unique’ is not a member of ‘std’
../main.cpp: In function ‘void render(const std::vector<Sphere>&)’:
../main.cpp:189:52: error: ‘make_unique’ is not a member of ‘std’
  189 |             threads[height * width + width] = std::make_unique<std::thread>([&]() -> void
      |                                                    ^~~~~~~~~~~
../main.cpp:189:52: note: ‘std::make_unique’ is only available from C++14 onwards

for the following lines :

threads[height * width + width] = std::make_unique<std::thread>([&]() -> void
{
    float xx = (2 * ((x + 0.5) * invWidth) - 1) * angle * aspectratio;
    float yy = (1 - 2 * ((y + 0.5) * invHeight)) * angle;
    Vec3f raydir(xx, yy, -1);
    raydir.normalize();
    *pixel = trace(Vec3f(0), raydir, spheres, 0);
});

threads being a vector declared like so:

std::vector<std::unique_ptr<std::thread>> threads(height * width);

Qt Creator documentation says that some features aren't supported using Meson here, but this does not include compiler version issues.

Upvotes: 0

Views: 812

Answers (1)

pmod
pmod

Reputation: 10997

It looks that everything is OK with meson options, you just forgot to add < memory> header (yes, error message is a bit confusing):

#include <memory>
...

Also, it could be due to setting c_std option for C++ compiler, since this option is for C compiler.

It's also possible that build directory is not (re)configured properly. To check currently configured options and flags you can with:

$ meson configure <build dir>

And to reconfigure:

$ meson setup --reconfigure <build dir>

BTW (it't nor related to question), this looks strange:

threads[height * width + width]  =

as it overlaps the vector, shouldn't it be ? :

threads[invHeight * width + invWidth]  =

TL;DR

This basic code :

#include <iostream>
#include <memory>

int main()
{
    std::cout << "Hello World!" << std::endl;
    std::unique_ptr<int> a = std::make_unique<int>();
    return 0;
}

will not work. Compiler tells me C++ 14 or plus is required to use make_unique. The issue is that I already put "project('ThreadPool', 'cpp', default_options : ['cpp_std=c++17'])" in the meson.build file, but for some reason this file is just not taken in account by Qt Creator : checking what are the build settings, the C++ version chosen is C++11.

Upvotes: 1

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