Re: Template type parameters with their own type parameters

[spir]

On 03/05/2011 04:02 AM, Peter Lundgren wrote:

I have a function that I think should look something like this:

MyStruct!T myFunc(T)(MyStruct!T x, ...) {
...
return MyStruct!T(...);
}

and the closest I can get to is:

T myFunc(T)(T x, ...) {
...
return T(...);
}

which works, but doesn't make clear the intended use and gets in the way of
overloading. How can I express the intent of the first version.


Maybe I do not exactly understand your problem; anyway, the following runs fine 
by me:


struct S (T) {
T v;
}

S!T inc (T) (S!T s) {
return S!T(s.v + 1);
}

unittest {
auto s1 = S!int(1);
auto s2 = inc(s1);
assert ( s2.v == 2 );
}

Could you provide (1) context (2) example (3) errors?

Denis
--
_
vita es estrany
spir.wikidot.com

Re: Template type parameters with their own type parameters

[Peter Lundgren]

== Quote from spir (denis.s...@gmail.com)'s article
 On 03/05/2011 04:02 AM, Peter Lundgren wrote:
  I have a function that I think should look something like this:
 
  MyStruct!T myFunc(T)(MyStruct!T x, ...) {
  ...
  return MyStruct!T(...);
  }
 
  and the closest I can get to is:
 
  T myFunc(T)(T x, ...) {
  ...
  return T(...);
  }
 
  which works, but doesn't make clear the intended use and gets in the way of
  overloading. How can I express the intent of the first version.
 Maybe I do not exactly understand your problem; anyway, the following runs 
 fine
 by me:
 struct S (T) {
  T v;
 }
 S!T inc (T) (S!T s) {
  return S!T(s.v + 1);
 }
 unittest {
  auto s1 = S!int(1);
  auto s2 = inc(s1);
  assert ( s2.v == 2 );
 }
 Could you provide (1) context (2) example (3) errors?
 Denis

Thanks for the help. I'd convinced myself that it didn't work and missed the
actual problem. I was mixing template type and template value parameters. What I
really wanted was this:

MyStruct!v myFunc(string v)(MyStruct!v x, ...) {
 ...
 return MyStruct!v(...);
}

Template type parameters with their own type parameters

[Peter Lundgren]

I have a function that I think should look something like this:

MyStruct!T myFunc(T)(MyStruct!T x, ...) {
...
return MyStruct!T(...);
}

and the closest I can get to is:

T myFunc(T)(T x, ...) {
...
return T(...);
}

which works, but doesn't make clear the intended use and gets in the way of
overloading. How can I express the intent of the first version.