On Thursday, 11 April 2024 at 03:17:36 UTC, John Dougan wrote:
Interesting. Thank you to both of you.
On Wednesday, 10 April 2024 at 17:38:21 UTC, Steven
Schveighoffer wrote:
On Wednesday, 10 April 2024 at 11:34:06 UTC, Richard (Rikki)
Andrew Cattermole wrote:
Place your attributes on the right hand side of the function,
not the left side.
Use the left side for attributes/type qualifiers that go on
the return type.
Just a word of warning, this explanation suggests putting
qualifiers on the left side would affect the return type, this
is not the case.
So in my example, what did I actually tell the compiler with
the placement of the attributes? And how was it different
between the function type alias declaration, and the actual
function declaration?
More specifically, what are the semantic differences below?
```d
alias FnPrefixT = @nogc nothrow @safe bool function(int);
// Versus
alias FnSuffixT = bool function(int) @nogc nothrow @safe;
```
So D can provide a nice mechanism to show what is happening --
`pragma(msg, ...)`
If I do that with the two types above I see something *very*
interesting:
```d
pragma(msg, FnPrefixT);
pragma(msg, FnSuffixT);
```
```
bool function(int) nothrow @nogc
bool function(int) nothrow @nogc @safe
```
That surprises me. `nothrow` and `@nogc` go onto the type, but
not `@safe` if put before the declaration? I have no idea why.
All I can think of is that it is a bug.
and
```d
@nogc nothrow @safe bool fnPrefix(int) { stuff }
// Versus
bool fnSuffix(int) @nogc nothrow @safe { stuff }
```
```d
pragma(msg, typeof(fnPrefix));
pragma(msg, typeof(fnSuffix));
```
```
nothrow @nogc @safe bool(int)
nothrow @nogc @safe bool(int)
```
(as expected)
-Steve
