How to use destroy and free.

[H. S. Teoh]

On Wed, May 04, 2022 at 10:04:53PM +0000, forkit via Digitalmars-d-learn wrote:
> On Wednesday, 4 May 2022 at 21:55:18 UTC, H. S. Teoh wrote:
> > On Wed, May 04, 2022 at 09:46:50PM +0000, forkit via Digitalmars-d-learn
> > wrote: [...]
[...]
> > > To deny a programmer the option to release the memory that was GC
> > > allocated within a particular scope, to be release immediately
> > > after that scope exits, seems kinda cruel.
> > [...]
> > 
> > 	scope ptr = GC.malloc(size);
> > 	scope(exit) GC.free(ptr);
> > 
> > 	... // use ptr however you like until end of scope
[...]
> that's cruel!
> 
> I just want 'scope-based deallocation of GC allocated memory'.
> 
> I just want to write one word for this to happen -> 'inscope'

-------
import std;

// Put this in some common module
auto scoped(T, Args...)(Args args) {
	static struct Result {
		private T* payload;
		ref T get() { return *payload; }
		alias get this;
		~this() {
			import core.memory : GC;
			writeln("dtor");
			GC.free(payload);
		}
	}
	return Result(new T(args));
}

// Then you can use it in just a single line, as below
void main() {
	struct MyType {
		int blah, blahblah;
	}

	auto data = scoped!MyType(10, 20);  // <--- like this
	data.blah = 123; // use data as you like

	// automatically frees on scope exit
}
-------


T

-- 
Тише едешь, дальше будешь.