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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

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.

bluetomcat 11y ago
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.
- nly 11y ago
  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
- f00fc0d3 11y ago
  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.
stinos 11y ago
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?
- f00fc0d3 11y ago
  Template metaprograming is nonsense, not simple type substitution. C++ templates are just too much, especially when mixed with substandard developers.
pjc50 11y ago
C has a generic: "void *". It just doesn't have any type safety.
- eutectic 11y ago
  It also has bad performance if you need to pass function pointers around.
  - pjc50 11y ago
    Is this noticeably worse than calling through the vtable?
    - eots 11y ago
      In C++ generics don't involve calling through a vtable.
ksherlock 11y ago
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)
- f00fc0d3 11y ago
  Yeah, but you still need to write those maxi, maxd :-(

bluetomcat 11y ago

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.

nly 11y ago
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
f00fc0d3 11y ago
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.

stinos 11y ago

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?

f00fc0d3 11y ago
Template metaprograming is nonsense, not simple type substitution. C++ templates are just too much, especially when mixed with substandard developers.

pjc50 11y ago

C has a generic: "void *". It just doesn't have any type safety.

eutectic 11y ago
It also has bad performance if you need to pass function pointers around.
- pjc50 11y ago
  Is this noticeably worse than calling through the vtable?
  - eots 11y ago
    In C++ generics don't involve calling through a vtable.

ksherlock 11y ago

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)

f00fc0d3 11y ago
Yeah, but you still need to write those maxi, maxd :-(