直接从C ++调用D函数 [英] Calling a D function directly from C++

问题描述

我已经浏览过 http://dlang.org/cpp_interface.html 例子，即使是那些其中一些C ++代码调用一些D代码，主函数驻留在D（因此被调用的二进制是从D源文件编译的）。在doc中的从C ++调用D的例子中有一个在D中定义的函数foo，它从C ++中的函数栏中调用，而bar又从D中的main函数调用。

I've gone through http://dlang.org/cpp_interface.html and in all of the examples, even those where some C++ code calls some D code, the main function resides in D (and so the binary being called is the one compiled from the D source file). The "calling D from C++" example in the doc has a function foo defined in D, which gets called from a function bar in C++, and bar in turn gets called from the main function in D.

是否可以从C ++函数调用D代码？我试图做一些简单的，像下面的，但不断得到生成错误：

Is it possible to just call D code from the C++ function? I'm trying to do something simple like the following, but keep getting build errors:

在D：

import std.stdio;

extern (C++) void CallFromCPlusPlusTest() {
  writeln("You can call me from C++");
}

然后在C ++中：

#include <iostream>

using namespace std;

void CallFromCPlusPlusTest();

int main() {
  cout << "hello world"<<"\n";
  CallFromCPlusPlusTest();
}

推荐答案

您的里程数可能会因所使用的C ++编译器而异。）

Yes it is possible, (your mileage may vary depending on the C++ compiler used.)

首先，您必须从C ++或D端初始化D运行时。

Firstly, you will have to initialized the D runtime, either from the C++ or the D side.

cpptestd.d：

cpptestd.d:

import std.stdio;

extern (C++) void CallFromCPlusPlusTest() {
  /*
   * Druntime could also be initialized from the D function:
  import core.runtime;
  Runtime.initialize();
  */
  writeln("You can call me from C++");
  //Runtime.terminate(); // and terminated
}

编译：
dmd -c cpptestd。 d

Compile with: dmd -c cpptestd.d

cpptest.cpp：

cpptest.cpp:

#include <iostream>

using namespace std;

void CallFromCPlusPlusTest();
extern "C" int rt_init();
extern "C" int rt_term();

int main() {
  cout << "hello world"<<"\n";
  rt_init(); // initialize druntime from C++
  CallFromCPlusPlusTest();
  rt_term(); // terminate druntime from C++
  return 0;
}

编译并链接：
g ++ cpptest.cpp cpptestd.o -L / path / to / phobos / -lphobos2 -pthread

Compile and link with: g++ cpptest.cpp cpptestd.o -L/path/to/phobos/ -lphobos2 -pthread

这在Linux上适用于我。

This works for me on Linux.

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