Windows bindings

[Rumbu]

On Wednesday, 17 February 2021 at 14:49:58 UTC, Steven 
Schveighoffer wrote:
> On 2/16/21 4:48 PM, Elronnd wrote:

What do you think?

//Usage:

@RAIIFree!CloseHandle
struct SomeHandle
{
     ptrdiff_t value;
}

SomeHandle CreateSomeHandle(int x, int y);
void DoSomethingWithSomeHandle(Handle h);
void CloseSomeHandle(SomeHandle h);

auto h = autoFree(CreateSomeHandle(42, 666));
DoSomethingWithSomeHandle(h);



//Implementation
struct RAIIFree(alias H)
{
     private alias Handler = H;
}

auto autoFree(T)(T handle)
{
     return RAIIWrapper!(T, FreeFunctionOf!T)(handle);
}

struct RAIIWrapper(Handle, alias CloseHandler)
{

     Handle s;
     alias s this;
     @disable this();
     @disable this(this);
     this(Handle value)
     {
         this.s = value;
     }
     ~this()
     {
         CloseHandler(s);
     }
}


private template FreeFunctionOf(T, A...)
{
     static if (A.length == 0)
     {
         alias attrs = __traits(getAttributes, T);
         static assert(attrs.length > 0, T.stringof ~ " doesn't 
have any attribute attached to it");
         alias FreeFunctionOf = FreeFunctionOf!(T, attrs);
     }
     else static if (A.length == 1)
     {
         static assert(isFreeHandler!(T, A[0]), T.stringof ~ " 
doesn't have a correct @RAIIFree attribute attached to it");
         alias FreeFunctionOf = A[0].Handler;
     }
     else static if (isFreeHandler!(T, A[0]))
         alias FreeFunctionOf = A[0].Handler;
     else
         alias FreeFunctionOf = FreeFunctionOf!(T, A[1 .. $]);
}

private template isFreeHandler(T, alias A)
{
     enum isFreeHandler = is(typeof(A.Handler))
         && is(typeof(A.Handler(T.init)));
}