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February 24, 2012 vfprintf equivalent in D | ||||
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Hi, Is there an equivalent to vfprintf(const char *fmt, , va_list ap) in D? -- Thanks, Sarath |
February 24, 2012 Re: vfprintf equivalent in D | ||||
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Posted in reply to Sarath Kumar | On Friday, February 24, 2012 05:22:58 Sarath Kumar wrote: > Hi, > > Is there an equivalent to vfprintf(const char *fmt, , va_list ap) in D? If you're dealing with C variadics, then your going to need to use C functions. D doesn't just recreate C functions (at least, the standard library doesn't). C functions get wrapped when doing so adds some benefit, but with something like this, there's no reason to. If you're using typesafe variadics void func(int[] arr...) then you can just pass the array to the next function. If you're using D-style variadics (which are similar to C variadics but include type information), maybe there is, I don't know. Probably. I never use them. However, the typical thing to do in D is to use variadic templates. That's what writefln does. void func(Args...)(Args args) And with that, you can just pass the arguments on to another function. http://dlang.org/function.html http://dlang.org/template.html - Jonathan M Davis |
February 24, 2012 Re: vfprintf equivalent in D | ||||
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On Thursday, February 23, 2012 21:38:27 Jonathan M Davis wrote:
> On Friday, February 24, 2012 05:22:58 Sarath Kumar wrote:
> > Hi,
> >
> > Is there an equivalent to vfprintf(const char *fmt, , va_list ap) in D?
>
> If you're dealing with C variadics, then your going to need to use C functions. D doesn't just recreate C functions (at least, the standard library doesn't). C functions get wrapped when doing so adds some benefit, but with something like this, there's no reason to.
>
>
> If you're using typesafe variadics
>
> void func(int[] arr...)
>
> then you can just pass the array to the next function.
>
>
> If you're using D-style variadics (which are similar to C variadics but include type information), maybe there is, I don't know. Probably. I never use them.
>
>
> However, the typical thing to do in D is to use variadic templates. That's what writefln does.
>
> void func(Args...)(Args args)
>
> And with that, you can just pass the arguments on to another function.
>
>
> http://dlang.org/function.html http://dlang.org/template.html
And if your intention was to specifically pass on arguments to writefln, then you can just do it, since it's a variadic template.
void myWritefln(Args...)(Args args)
{
writefln(args);
}
But if you're looking to specifically pass on a C variadic, then use C's vfprintf.
- Jonathan M Davis
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February 24, 2012 Re: vfprintf equivalent in D | ||||
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Posted in reply to Sarath Kumar | On Fri, Feb 24, 2012 at 05:22:58AM +0000, Sarath Kumar wrote: > Hi, > > Is there an equivalent to vfprintf(const char *fmt, , va_list ap) in D? [...] You don't need one. You can just write: void myWritelnWrapper(T...)(T args) { ... // insert your own processing here, modify args // if you like, etc. writeln(args); } T -- Life would be easier if I had the source code. -- YHL |
February 24, 2012 Re: vfprintf equivalent in D | ||||
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Posted in reply to H. S. Teoh | Thanks Jonathan and Teoh. I just have to pass the var args in my function to writefln and Variadic templates is the right solution for me. -- Thanks, Sarath |
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