Potential for leaking references from alias this aside, is there some reason that I shouldn't do this for all my C++-like RAII needs:

class A
{
	~this(){ import std.stdio; writeln("hello"); }
}

auto RAII(T)()
if (is(T == class))
{
	struct Inner
	{
		private ubyte[__traits(classInstanceSize, T)] buff;
		T c;
		alias c this;
		
		~this()
		{
			destroy(c);
		}
	}
	Inner tmp;
	import std.conv : emplace;
	tmp.c = tmp.buff.emplace!T;
	return tmp;
}

void main()
{
	auto a = RAII!A;
}

On Wednesday, 9 March 2016 at 10:28:06 UTC, John Colvin wrote:
> Potential for leaking references from alias this aside, is there some reason that I shouldn't do this for all my C++-like RAII needs:
>
> class A
> {
> 	~this(){ import std.stdio; writeln("hello"); }
> }
>
> auto RAII(T)()
> if (is(T == class))
> {
> 	struct Inner
> 	{
> 		private ubyte[__traits(classInstanceSize, T)] buff;
> 		T c;
> 		alias c this;
> 		
> 		~this()
> 		{
> 			destroy(c);
> 		}
> 	}
> 	Inner tmp;
> 	import std.conv : emplace;
> 	tmp.c = tmp.buff.emplace!T;
> 	return tmp;
> }
>
> void main()
> {
> 	auto a = RAII!A;
> }

That's almost literally what std.typecons.scoped does.

On Wednesday, 9 March 2016 at 10:48:30 UTC, cym13 wrote:
> On Wednesday, 9 March 2016 at 10:28:06 UTC, John Colvin wrote:
>> Potential for leaking references from alias this aside, is there some reason that I shouldn't do this for all my C++-like RAII needs:
>>
>> class A
>> {
>> 	~this(){ import std.stdio; writeln("hello"); }
>> }
>>
>> auto RAII(T)()
>> if (is(T == class))
>> {
>> 	struct Inner
>> 	{
>> 		private ubyte[__traits(classInstanceSize, T)] buff;
>> 		T c;
>> 		alias c this;
>> 		
>> 		~this()
>> 		{
>> 			destroy(c);
>> 		}
>> 	}
>> 	Inner tmp;
>> 	import std.conv : emplace;
>> 	tmp.c = tmp.buff.emplace!T;
>> 	return tmp;
>> }
>>
>> void main()
>> {
>> 	auto a = RAII!A;
>> }
>
> That's almost literally what std.typecons.scoped does.

Ok, I forgot std.typecons.scoped, nothing to see here .....