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A comment on What if anything have we learned from C++? [video]. Parent comment

Re:What if anything have we learned from C++? [video] by f00fc0d3 on Friday July 24, 2015 @06:30AM (#9941055)
C99 is nice, but C still lacks generic. I am not talking about C++ template nonsense, but not having to write max element search for every primitive type.

I am working in DSP project which was started with typical C++ OO BS, finally with ended up with C compiled as C++ + some simple templates for cases as above.

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Re:What if anything have we learned from C++? [video] by pjc50 on Friday July 24, 2015 @06:55AM (#9941120)
C has a generic: "void *". It just doesn't have any type safety.
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Re:What if anything have we learned from C++? [video] by eutectic on Friday July 24, 2015 @08:17AM (#9941396)
It also has bad performance if you need to pass function pointers around.
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Re:What if anything have we learned from C++? [video] by pjc50 on Friday July 24, 2015 @09:20AM (#9941746)
Is this noticeably worse than calling through the vtable?
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Re:What if anything have we learned from C++? [video] by eots on Friday July 24, 2015 @10:16AM (#9942118)
In C++ generics don't involve calling through a vtable.
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Re:What if anything have we learned from C++? [video] by ksherlock on Friday July 24, 2015 @08:26AM (#9941432)
C11 has type generic macros. You can build your own with the _Generic statement.

    int maxi(int, int);
    double: maxd(double, double);
    ...
    #define max(x) _Generic((x), int: maxi, double: maxd, ...default: maxi)
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Re:What if anything have we learned from C++? [video] by f00fc0d3 on Friday July 24, 2015 @09:32AM (#9941824)
Yeah, but you still need to write those maxi, maxd :-(
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Re:What if anything have we learned from C++? [video] by stinos on Friday July 24, 2015 @06:48AM (#9941099)
I am not talking about C++ template nonsense, but not having to write max element search for every primitive type

How is it template 'nonsense', when those templates do exactly that?

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Re:What if anything have we learned from C++? [video] by f00fc0d3 on Friday July 24, 2015 @07:27AM (#9941197)
Template metaprograming is nonsense, not simple type substitution. C++ templates are just too much, especially when mixed with substandard developers.
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Re:What if anything have we learned from C++? [video] by bluetomcat on Friday July 24, 2015 @06:42AM (#9941080)
Using statement expressions and the typeof extension, you are able to write function-like, type-generic, scope-insensitive macros like this one:

    #define MAX(a,b) ({ \
        typeof (a) _a = (a); \
        typeof (b) _b = (b); \
        _a > _b ? _a : _b; \
    })
The inability to write template functions can be compensated by designing your function so that it takes a function pointer where the type-specific action occurs.
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Re:What if anything have we learned from C++? [video] by nly on Friday July 24, 2015 @07:55AM (#9941308)
Your MAX has no respect for namespaces or scopes. A real world macro is probably going to be called MYLIBRARY_MAX to avoid this. Secondly the C++ lambda solution is just easier to read.

    auto max = [](auto a, auto b) { 
        return (a > b) ? a : b;
    };

    max (3.1415, 42); // returns double
    max (42ul, 78u); // returns unsigned long
    max (17, 16); // returns int
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Re:What if anything have we learned from C++? [video] by f00fc0d3 on Friday July 24, 2015 @07:25AM (#9941194)
Typeof is not standard and many DSP compilers do not implement that. Secondly I meant max search in array, not between to scalar values which is trivial. I really don't want to have for(...) inlined everywhere.
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