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digitalmars.D - UFCS and operator overloading

reply Jens Mueller <jens.k.mueller gmx.de> writes:
Hi,

from my understanding UFCS is supposed to work with operator overloading. I.e.
in the following a + b should work

struct Foo {}

Foo opBinary(string op)(Foo lhs, Foo rhs) if (op == "+")
{
    return Foo.init;
}

unittest
{
    Foo a, b;
    a + b; // fails to compile
}

Is UFCS supposed to work with operator overloading, isn't it?

Jens
May 07 2012
next sibling parent reply "Nick Sabalausky" <SeeWebsiteToContactMe semitwist.com> writes:
"Jens Mueller" <jens.k.mueller gmx.de> wrote in message 
news:mailman.391.1336410464.24740.digitalmars-d puremagic.com...

 Hi,

 from my understanding UFCS is supposed to work with operator overloading. 
 I.e.
 in the following a + b should work

 struct Foo {}

 Foo opBinary(string op)(Foo lhs, Foo rhs) if (op == "+")
 {
    return Foo.init;
 }

 unittest
 {
    Foo a, b;
    a + b; // fails to compile
 }

 Is UFCS supposed to work with operator overloading, isn't it?

 Jens



I don't know why that doesn't work (unless you just need to make it "auto c 
= a + b;" so it isn't a "statement has no effect"?), but FWIW that's not an 
example of UFCS. UFCS would mean calling your opBinary above like this:

a.opBinary!"+"(b)

Instead of this:

opBinary!"+"(a, b)
May 07 2012
parent reply Timon Gehr <timon.gehr gmx.ch> writes:
On 05/07/2012 10:37 PM, Nick Sabalausky wrote:

 "Jens Mueller"<jens.k.mueller gmx.de>  wrote in message
 news:mailman.391.1336410464.24740.digitalmars-d puremagic.com...

 Hi,

 from my understanding UFCS is supposed to work with operator overloading.
 I.e.
 in the following a + b should work

 struct Foo {}

 Foo opBinary(string op)(Foo lhs, Foo rhs) if (op == "+")
 {
     return Foo.init;
 }

 unittest
 {
     Foo a, b;
     a + b; // fails to compile
 }

 Is UFCS supposed to work with operator overloading, isn't it?

 Jens



 I don't know why that doesn't work (unless you just need to make it "auto c
 = a + b;" so it isn't a "statement has no effect"?), but FWIW that's not an
 example of UFCS. UFCS would mean calling your opBinary above like this:

 a.opBinary!"+"(b)

 Instead of this:

 opBinary!"+"(a, b)



  a + b => a.opBinary!"+"(b) => opBinary!"+"(a, b)
        ^                    ^
standard rewrite           UFCS
May 08 2012
parent "Nick Sabalausky" <SeeWebsiteToContactMe semitwist.com> writes:
"Timon Gehr" <timon.gehr gmx.ch> wrote in message 
news:jobo5r$1cf7$1 digitalmars.com...

 On 05/07/2012 10:37 PM, Nick Sabalausky wrote:

 I don't know why that doesn't work (unless you just need to make it "auto 
 c
 = a + b;" so it isn't a "statement has no effect"?), but FWIW that's not 
 an
 example of UFCS. UFCS would mean calling your opBinary above like this:

 a.opBinary!"+"(b)

 Instead of this:

 opBinary!"+"(a, b)



  a + b => a.opBinary!"+"(b) => opBinary!"+"(a, b)
        ^                    ^
 standard rewrite           UFCS



/facepalm

Yea, I get it now ;)
May 08 2012
prev sibling next sibling parent Gor Gyolchanyan <gor.f.gyolchanyan gmail.com> writes:
Still, not having non-member operator overloads is very bothersome.

On Tue, May 8, 2012 at 12:37 AM, Nick Sabalausky
<SeeWebsiteToContactMe semitwist.com> wrote:

 "Jens Mueller" <jens.k.mueller gmx.de> wrote in message
 news:mailman.391.1336410464.24740.digitalmars-d puremagic.com...

 Hi,

 from my understanding UFCS is supposed to work with operator overloading=







 I.e.
 in the following a + b should work

 struct Foo {}

 Foo opBinary(string op)(Foo lhs, Foo rhs) if (op =3D=3D "+")
 {
 =C2=A0 =C2=A0return Foo.init;
 }

 unittest
 {
 =C2=A0 =C2=A0Foo a, b;
 =C2=A0 =C2=A0a + b; // fails to compile
 }

 Is UFCS supposed to work with operator overloading, isn't it?

 Jens



 I don't know why that doesn't work (unless you just need to make it "auto=




 =3D a + b;" so it isn't a "statement has no effect"?), but FWIW that's no=




 example of UFCS. UFCS would mean calling your opBinary above like this:

 a.opBinary!"+"(b)

 Instead of this:

 opBinary!"+"(a, b)





--=20
Bye,
Gor Gyolchanyan.
May 07 2012
prev sibling parent Jens Mueller <jens.k.mueller gmx.de> writes:
Timon Gehr wrote:

 On 05/07/2012 10:37 PM, Nick Sabalausky wrote:

"Jens Mueller"<jens.k.mueller gmx.de>  wrote in message
news:mailman.391.1336410464.24740.digitalmars-d puremagic.com...

Hi,

from my understanding UFCS is supposed to work with operator overloading.
I.e.
in the following a + b should work

struct Foo {}

Foo opBinary(string op)(Foo lhs, Foo rhs) if (op == "+")
{
    return Foo.init;
}

unittest
{
    Foo a, b;
    a + b; // fails to compile
}

Is UFCS supposed to work with operator overloading, isn't it?

Jens



I don't know why that doesn't work (unless you just need to make it "auto c
= a + b;" so it isn't a "statement has no effect"?), but FWIW that's not an
example of UFCS. UFCS would mean calling your opBinary above like this:

a.opBinary!"+"(b)

Instead of this:

opBinary!"+"(a, b)



  a + b => a.opBinary!"+"(b) => opBinary!"+"(a, b)
        ^                    ^
 standard rewrite           UFCS



Yes. That's how it should be. I reported it.

Jens
May 08 2012