www.digitalmars.com         C & C++   DMDScript  

digitalmars.D.learn - std.traits and std.string incompatible ?

reply Wilfried Kirschenmann <wilfried.kirschenmann gmail.com> writes:
Hi,

When running the following file:


import std.string, std.traits;
void main(string[] args){
	bool test = isNumeric(args[0]);
}

I get the error :
dmd2/linux/bin/../../src/phobos/std/traits.d(2576): Error: template
std.traits.isNumeric(T) is not a function template

Is this a bug or is there something deprecated ?

Wilfried
Mar 08 2011
parent reply =?UTF-8?B?QWxpIMOHZWhyZWxp?= <acehreli yahoo.com> writes:
On 03/08/2011 08:24 AM, Wilfried Kirschenmann wrote:

 Hi,

 When running the following file:


 import std.string, std.traits;
 void main(string[] args){
 	bool test = isNumeric(args[0]);
 }

 I get the error :
 dmd2/linux/bin/../../src/phobos/std/traits.d(2576): Error: template
 std.traits.isNumeric(T) is not a function template

 Is this a bug or is there something deprecated ?

 Wilfried



isNumeric is a template. You are supposed to give it a type:

   if (isNumeric!SomeType)

or at compile time:

   static if (isNumeric!SomeType)

It doesn't work with string values. Although unnecessary, you could do this:

     bool test = isNumeric!(typeof(args[0]));

Ali
Mar 08 2011
parent reply "Nick Sabalausky" <a a.a> writes:
"Ali Çehreli" <acehreli yahoo.com> wrote in message 
news:il5pge$nrr$1 digitalmars.com...

 On 03/08/2011 08:24 AM, Wilfried Kirschenmann wrote:

 Hi,

 When running the following file:


 import std.string, std.traits;
 void main(string[] args){
 bool test = isNumeric(args[0]);
 }

 I get the error :
 dmd2/linux/bin/../../src/phobos/std/traits.d(2576): Error: template
 std.traits.isNumeric(T) is not a function template

 Is this a bug or is there something deprecated ?

 Wilfried



 isNumeric is a template. You are supposed to give it a type:

   if (isNumeric!SomeType)

 or at compile time:

   static if (isNumeric!SomeType)

 It doesn't work with string values. Although unnecessary, you could do 
 this:

     bool test = isNumeric!(typeof(args[0]));


No, there's an isNumeric in *both* std.traits and std.string. The one in 
std.traits is a template that takes a type. But the one in std.string is a 
function that takes a string and checks if the value of the string is 
numeric.

I'm on the latest D2 (2.052) and I just tried the example and got the same 
result. But if I *only* import std.string then it works. So it sounds like a 
bug: I forget the exact details of the rules involving overloading across 
modules, but one of two things should happen with the original example:

A. It should know that you meant std.string.isNumeric because of how you're 
calling it.

or:

B. It should complain that there's an ambiguity between std.string.isNumeric 
and std.traits.isNumeric and require you to disambiguate with either 
"std.traits." or "std.string."

I'm not sure which of those it's supposed to do, but it's clearly not doing 
either, so I'd file it as a bug: http://d.puremagic.com/issues/
Mar 08 2011
next sibling parent Jonathan M Davis <jmdavisProg gmx.com> writes:
On Tuesday, March 08, 2011 13:24:44 Nick Sabalausky wrote:

 "Ali =C7ehreli" <acehreli yahoo.com> wrote in message
 news:il5pge$nrr$1 digitalmars.com...
=20

 On 03/08/2011 08:24 AM, Wilfried Kirschenmann wrote:

 Hi,
=20
 When running the following file:
=20

 import std.string, std.traits;
 void main(string[] args){
 bool test =3D isNumeric(args[0]);
 }
=20
 I get the error :
 dmd2/linux/bin/../../src/phobos/std/traits.d(2576): Error: template
 std.traits.isNumeric(T) is not a function template
=20
 Is this a bug or is there something deprecated ?
=20
 Wilfried


=20
 isNumeric is a template. You are supposed to give it a type:
   if (isNumeric!SomeType)
=20
 or at compile time:
   static if (isNumeric!SomeType)
=20
 It doesn't work with string values. Although unnecessary, you could do
=20
 this:
     bool test =3D isNumeric!(typeof(args[0]));


=20
 No, there's an isNumeric in *both* std.traits and std.string. The one in
 std.traits is a template that takes a type. But the one in std.string is a
 function that takes a string and checks if the value of the string is
 numeric.
=20
 I'm on the latest D2 (2.052) and I just tried the example and got the same
 result. But if I *only* import std.string then it works. So it sounds like
 a bug: I forget the exact details of the rules involving overloading
 across modules, but one of two things should happen with the original
 example:
=20
 A. It should know that you meant std.string.isNumeric because of how you'=


re

 calling it.
=20
 or:
=20
 B. It should complain that there's an ambiguity between
 std.string.isNumeric and std.traits.isNumeric and require you to
 disambiguate with either "std.traits." or "std.string."
=20
 I'm not sure which of those it's supposed to do, but it's clearly not doi=


ng

 either, so I'd file it as a bug: http://d.puremagic.com/issues/


isNumeric in std.string is a function. In std.traits, it's an eponymous=20
template. The eponymous template should require the !. There's no function =
to=20
feed the argument to. There shouldn't be any ambiguity of any kind. Overloa=
d set=20
rules and whatnot should have nothing to do with this. This is definitely a=
 bug.

=2D Jonathan M Davis
Mar 08 2011
prev sibling parent Jonathan M Davis <jmdavisProg gmx.com> writes:
On Tuesday, March 08, 2011 16:11:09 Jonathan M Davis wrote:

 On Tuesday, March 08, 2011 13:24:44 Nick Sabalausky wrote:

 "Ali =C7ehreli" <acehreli yahoo.com> wrote in message
 news:il5pge$nrr$1 digitalmars.com...
=20

 On 03/08/2011 08:24 AM, Wilfried Kirschenmann wrote:

 Hi,
=20
 When running the following file:
=20

 import std.string, std.traits;
 void main(string[] args){
 bool test =3D isNumeric(args[0]);
 }
=20
 I get the error :
 dmd2/linux/bin/../../src/phobos/std/traits.d(2576): Error: template
 std.traits.isNumeric(T) is not a function template
=20
 Is this a bug or is there something deprecated ?
=20
 Wilfried


=20
 isNumeric is a template. You are supposed to give it a type:
   if (isNumeric!SomeType)
=20
 or at compile time:
   static if (isNumeric!SomeType)
=20
 It doesn't work with string values. Although unnecessary, you could do
=20
 this:
     bool test =3D isNumeric!(typeof(args[0]));


=20
 No, there's an isNumeric in *both* std.traits and std.string. The one in
 std.traits is a template that takes a type. But the one in std.string is
 a function that takes a string and checks if the value of the string is
 numeric.
=20
 I'm on the latest D2 (2.052) and I just tried the example and got the
 same result. But if I *only* import std.string then it works. So it
 sounds like a bug: I forget the exact details of the rules involving
 overloading across modules, but one of two things should happen with the
 original example:
=20
 A. It should know that you meant std.string.isNumeric because of how
 you're calling it.
=20
 or:
=20
 B. It should complain that there's an ambiguity between
 std.string.isNumeric and std.traits.isNumeric and require you to
 disambiguate with either "std.traits." or "std.string."
=20
 I'm not sure which of those it's supposed to do, but it's clearly not
 doing either, so I'd file it as a bug: http://d.puremagic.com/issues/


=20
 isNumeric in std.string is a function. In std.traits, it's an eponymous
 template. The eponymous template should require the !. There's no function
 to feed the argument to. There shouldn't be any ambiguity of any kind.
 Overload set rules and whatnot should have nothing to do with this. This
 is definitely a bug.


Reported: http://d.puremagic.com/issues/show_bug.cgi?id=3D5721

=2D Jonathan M Davis
Mar 08 2011