Enable compiler selection in vcpkg.json

[Melnytskyi]

I propose adding the ability to select the default compiler directly in the vcpkg.json manifest file. This feature would allow users to specify the compiler for building dependencies and set the CMake variables CMAKE_C_COMPILER and CMAKE_CXX_COMPILER for proper binary linking.

Current Approach:

Currently, setting the compiler requires using overlay triplets, which is not user-friendly. Users must create their own triplet and overlay triplet or use one from GitHub, often needing to fix bugs. This process is cumbersome and slows down the development workflow compared to the otherwise straightforward dependency management provided by vcpkg.

Suggested Improvement:

Allowing compiler selection in the vcpkg.json manifest would:

• Simplify Configuration: Users can directly specify the desired compiler in the manifest file, eliminating the need for additional triplet files.
• Improve Usability: Make the process more intuitive and accessible, especially for new users.
• Enhance Productivity: Reduce setup time and potential errors associated with overlay triplets, leading to a smoother development experience. This feature would streamline the development process, making vcpkg even more powerful and user-friendly.

Possibly Formats:

{
    "name": "Name",
    "version": "1.0.0",
    "compiler":  "gcc",
    "dependencies":[]
}

{
    "name": "Name",
    "version": "1.0.0",
    "compiler": {
        "name": "gcc",
        "version": "9..10.2",
        "path": "Optional path"
    },
    "dependencies": []
}

[Osyotr]

IMHO, this is impossible to maintain. And it's vcpkg that must be told to use some toolchain, not the other way around.

[JonLiu1993]

@Melnytskyi, Thanks for posting this issue, This feature is very difficult to add and maintain, because different compilers and different versions will affect the installation and compilation of different versions of ports in vcpkg, which is very inconvenient for users and maintainers.