dmd/compiler/test/fail_compilation/union_initialization.d

/*
https://issues.dlang.org/show_bug.cgi?id=20068

TEST_OUTPUT:
---
fail_compilation/union_initialization.d(19): Error: accessing overlapped field `B.p` with pointers is not allowed in a `@safe` function
fail_compilation/union_initialization.d(25): Error: accessing overlapped field `B.p` with pointers is not allowed in a `@safe` function
---
*/

union B
{
	int i;
	int* p;

	@safe this(int* p)
	{
		this.p = p;
		int* x = this.p;
	}

	@safe this(int** i)
	{
		this.p = null;
		this.p = *i;
	}
}

/*
TEST_OUTPUT:
---
fail_compilation/union_initialization.d(109): Error: immutable field `p` initialized multiple times
fail_compilation/union_initialization.d(108):        Previous initialization is here.
---
*/
#line 100

union C
{
	int i;
	immutable int* p;

	@safe this(immutable int* p)
	{
		this.p = p;
		this.p = null;
	}
}

/*
https://issues.dlang.org/show_bug.cgi?id=21229

TEST_OUTPUT:
---
fail_compilation/union_initialization.d(223): Error: field `union_` must be initialized in constructor
fail_compilation/union_initialization.d(223): Error: field `proxy` must be initialized in constructor
---
*/
#line 200

struct NeedsInit
{
	int var;
	long lo;
	@disable this();
}

union Union
{
	NeedsInit ni;
}

union Proxy
{
	Union union_;
}

struct S
{
	Union union_;
	Proxy proxy;

	this(int arg)
	{
		union_.ni.var = arg;
		proxy.union_.ni.var = arg;
	}
}