• Andrea Fontana (3/3) Aug 26 2015 I wonder if there's a way to add UDA to functions at compile-time
• Alex Parrill (8/12) Aug 26 2015 What do you mean? UDAs are already specified at compile time.
• Andrea Fontana (6/19) Aug 26 2015 __traits(setAttributes, ...)
• Alex Parrill (17/22) Aug 26 2015 Lots of compile-time information is fixed after the symbol is

"Andrea Fontana" <nospam example.com> writes:

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

"Alex Parrill" <initrd.gz gmail.com> writes:

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");

"Andrea Fontana" <nospam example.com> writes:

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, ...);

"Alex Parrill" <initrd.gz gmail.com> writes:

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.