gcc/testsuite/gdc.test/compilable/dtoh_extern_type.d

/*
https://issues.dlang.org/show_bug.cgi?id=21219

REQUIRED_ARGS: -o- -HC
TEST_OUTPUT:
---
// Automatically generated by Digital Mars D Compiler

#pragma once

#include <assert.h>
#include <stddef.h>
#include <stdint.h>
#include <math.h>

#ifdef CUSTOM_D_ARRAY_TYPE
#define _d_dynamicArray CUSTOM_D_ARRAY_TYPE
#else
/// Represents a D [] array
template<typename T>
struct _d_dynamicArray final
{
    size_t length;
    T *ptr;

    _d_dynamicArray() : length(0), ptr(NULL) { }

    _d_dynamicArray(size_t length_in, T *ptr_in)
        : length(length_in), ptr(ptr_in) { }

    T& operator[](const size_t idx) {
        assert(idx < length);
        return ptr[idx];
    }

    const T& operator[](const size_t idx) const {
        assert(idx < length);
        return ptr[idx];
    }
};
#endif
#if !defined(_d_real)
#define _d_real long double
#endif

class ClassFromStruct final
{
public:
    void foo();
    ClassFromStruct()
    {
    }
};

class ClassFromClass
{
public:
    virtual void foo();
};

struct StructFromStruct final
{
    void foo();
    StructFromStruct()
    {
    }
};

struct StructFromClass
{
    virtual void foo();
};

struct Floats final
{
    float f;
    double d;
    _d_real r;
    double nan;
    double inf;
    double nInf;
    Floats() :
        f(1.23F),
        d(4.56),
        r(7.89L),
        nan(NAN),
        inf(INFINITY),
        nInf(-INFINITY)
    {
    }
    Floats(float f, double d = 4.56, _d_real r = 7.89L, double nan = NAN, double inf = INFINITY, double nInf = -INFINITY) :
        f(f),
        d(d),
        r(r),
        nan(nan),
        inf(inf),
        nInf(nInf)
        {}
};

struct Null final
{
    _d_dynamicArray< const char > null_;
    Null() :
        null_()
    {
    }
    Null(_d_dynamicArray< const char > null_) :
        null_(null_)
        {}
};

struct Wrapper final
{
    Null n1;
    Null n2;
    Wrapper() :
        n1(Null({ 5, "Hello" })),
        n2(Null({}))
    {
    }
    Wrapper(Null n1, Null n2 = Null({})) :
        n1(n1),
        n2(n2)
        {}
};

extern const _d_dynamicArray< const char > helloWorld;
---
*/

extern (C++, class) struct ClassFromStruct
{
    void foo() {}
}

extern (C++, class) class ClassFromClass
{
    void foo() {}
}

extern (C++, struct) struct StructFromStruct
{
    void foo() {}
}

extern (C++, struct) class StructFromClass
{
    void foo() {}
}

extern(C++) struct Floats
{
    float f = 1.23f;
    double d = 4.56;
    real r = 7.89L;

    double nan = double.nan;
    double inf = double.infinity;
    double nInf = -double.infinity;
}

extern (C++) struct Null
{
    string null_ = null;
}

extern (C++) struct Wrapper
{
    Null n1 = Null("Hello");
    Null n2 = Null(null);
}

extern(C++) __gshared immutable string helloWorld = `"Hello\World!"`;