I wonder if there's a way to add UDA to functions at compile-time (so I can read later from other parts of application).

Andrea

On Wednesday, 26 August 2015 at 08:19:04 UTC, Andrea Fontana wrote:
> I wonder if there's a way to add UDA to functions at compile-time (so I can read later from other parts of application).
>
> Andrea

What do you mean? UDAs are already specified at compile time.


	@("hello")
	void foo() {
		
	}

	static assert(__traits(getAttributes, foo)[0] == "hello");

On Wednesday, 26 August 2015 at 14:01:00 UTC, Alex Parrill wrote:
> On Wednesday, 26 August 2015 at 08:19:04 UTC, Andrea Fontana wrote:
>> I wonder if there's a way to add UDA to functions at compile-time (so I can read later from other parts of application).
>>
>> Andrea
>
> What do you mean? UDAs are already specified at compile time.
>
>
> 	@("hello")
> 	void foo() {
> 		
> 	}
>
> 	static assert(__traits(getAttributes, foo)[0] == "hello");

__traits(setAttributes, ...)

It would be useful, for example, if I have a list of functions to mark. Let's say

enum toExport = ["oldFunction", "thisToo"];
foreach(d; toExport) __traits(setAttributes, ...);

On Wednesday, 26 August 2015 at 14:29:30 UTC, Andrea Fontana wrote:
>
> __traits(setAttributes, ...)
>
> It would be useful, for example, if I have a list of functions to mark. Let's say
>
> enum toExport = ["oldFunction", "thisToo"];
> foreach(d; toExport) __traits(setAttributes, ...);

Lots of compile-time information is fixed after the symbol is defined, making it effectively immutable. There's not, for example, a `__traits(setType, var)`.

If you want to apply a UDA to many functions at once, you can use the block syntax:

	@("hello") {
		void foo1() {}
		void foo2() {}
	}

	// or alternatively

	@("hello"):

	void foo3() {}
	void foo4() {}

Also if you're talking about the `export` keyword, then that's not a UDA.