ALL_OF invalid conversion from 'char' to 'const char*' [-fpermissive]

Question

I have a problem when I compile my code.

template<class InputIterator, class UnaryPredicate>
  bool all_of (InputIterator first, InputIterator last, UnaryPredicate pred)
{
  while (first!=last) {
    if (!pred(*first)) return false;
    ++first;
  }
  return true;
}

I took the code from http://www.cplusplus.com/reference/algorithm/all_of/?kw=all_of.

I'm using Code::blocks 12.11 and I have the following errors:

C:\Users\PC-HP\Desktop\chiffre\romain\main.cpp||In instantiation of 'bool all_of(InputIterator, InputIterator, UnaryPredicate) [with InputIterator = __gnu_cxx::__normal_iterator >; UnaryPredicate = bool (*)(std::basic_string)]':|

C:\Users\PC-HP\Desktop\chiffre\romain\main.cpp|84|required from here|

C:\Users\PC-HP\Desktop\chiffre\romain\main.cpp|13|error: invalid conversion from 'char' to 'const char*' [-fpermissive]|

c:\program files\codeblocks\mingw\bin..\lib\gcc\mingw32\4.7.1\include\c++\bits\basic_string.tcc|214|error: initializing argument 1 of 'std::basic_string<_CharT, _Traits, _Alloc>::basic_string(const _CharT*, const _Alloc&) [with _CharT = char; _Traits = std::char_traits; _Alloc = std::allocator]' [-fpermissive]|

||=== Build finished: 2 errors, 2 warnings (0 minutes, 1 seconds) ===|

line 84:

while(!all_of(romain.begin(), romain.end(), IsRoman))

There is my entire code: http://pastebin.com/k0KYNB6H I don't use c++11.

Dietmar Kühl Dietmar Kühl · Accepted Answer · 2013-12-29T18:57:57

According to your error message your predicate takes a std::basic_string (probably really a std::string) but you are iterating over a sequence of chars. These won't convert to a std::string. You want to pass a predicate like

bool IsRoman(char c) {
    return ...;
}

ALL_OF invalid conversion from 'char' to 'const char*' [-fpermissive]

2 Answers