VSCode：为 static 分析设置 C/C++ 预处理器宏

Question

I am developing a library which lets user set a crucial type alias, or do it through preprocessor directives. This type alias (or the directive) is undeclared in the library, by design. Thus, when developing my code I get annoying error messages and squiggles for this undeclared type. This could be avoided if I declare a temporary type for it somewhere. However, I do not like the idea of declaring it when I work with the code and then remove it when I publish it. It is also bug prone, since I could easily forget to remove it.

My question is: Can I define preprocessor directives for VS Code's static analysis (IntelliSense? C/C++ Extension)?

That would let me consider the analysis like what a well defined type alias would produce. And avoid annoying error messages/squiggles.

---

Minimal reproducable example:

Online compiler example

tCore.hpp

#pragma once

#include <string>

// User is responsible of declaring the tCore type

// tCore interface methods 
template<typename TCore>
std::string printImpl();

tPrint.hpp

#pragma once

#include <iostream>

class tPrint {
  public:
    tPrint() = default;
      
    void print() const {
        std::cout << printImpl<tCore>() << std::endl; // <-- Static analysis error here!
    }
};

tFoo.hpp - tCore candidate

#pragma once

#include <string>
#include "tCore.hpp"

struct tFoo {};

template<>
std::string printImpl<tFoo>() {
    return "tFoo";
}

main.cpp

#include <tFoo.hpp>

using tCore = tFoo;

int main() {
    tPrint p{};
    p.print();  // -> "tFoo"
    return 0;
}

Answer 1

I found out it was IntelliSense causing the error through the C/C++ Extension .

I also found an option of adding compiler arguments to IntelliSense , which is exactly what I was looking for.

Either through the UI:

Press F1 -> > C/C++: Edit Configurations (UI) -> Scroll down to Defines

Or via the JSON:

c_cpp_properties.json configurations has a field defines which holds any compiler arguments.