[c++] strchr jako argument templata się nie kompiluje

Article View: pl.comp.lang.c

Article #308826

#308826

From: Wojciech Muła
Date: Thu, 06 Oct 2016 17:00

38 lines
2302 bytes

GCC 4.9.2, taki kod:

---
#include <cstring>

const char* my_strchr(const char* s, int c) {
    return s + c;
}

template <typename STRLEN>
const char* foo(STRLEN strchr_fun, const char* s, int c) {
    return strchr_fun(s, c);
}

int main() {
    foo(my_strchr, "hello world", '?');
    foo(std::strchr, "hello world", '?');
}
---

$ gcc -std=c++14 bug.cpp

bug.cpp: In function ‘int main()’:
bug.cpp:14:40: error: no matching function for call to ‘foo(<unresolved overloaded function type>, const char [12], char)’
     foo(std::strchr, "hello world", '?');
                                        ^
bug.cpp:14:40: note: candidate is:
bug.cpp:8:13: note: template<class STRLEN> const char* foo(STRLEN, const char*, int)
 const char* foo(STRLEN strchr_fun, const char* s, int c) {
             ^
bug.cpp:8:13: note:   template argument deduction/substitution failed:
bug.cpp:14:40: note:   couldn't deduce template parameter ‘STRLEN’
     foo(std::strchr, "hello world", '?');

Po prostu nie rozumiem. Ten strchr to jest jakieś makro,
czy co?

w.

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Subject: [c++] strchr jako argument templata się nie
 kompiluje
From: Wojciech Muła <wojciech_mula@poczta.onet.pl>
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