Eroare de compilare: user.cpp: In member function ‘bool HashEquality::operator()(const real&, const real&) const’: user.cpp:110:20: error: call of overloaded ‘abs(real)’ is ambiguous return abs(a - b) < 1e-6; ^ In file included from /usr/include/c++/6/cstdlib:75:0, from /usr/include/c++/6/ext/string_conversions.h:41, from /usr/include/c++/6/bits/basic_string.h:5417, from /usr/include/c++/6/string:52, from /usr/include/c++/6/bits/locale_classes.h:40, from /usr/include/c++/6/bits/ios_base.h:41, from /usr/include/c++/6/ios:42, from /usr/include/c++/6/istream:38, from /usr/include/c++/6/fstream:38, from user.cpp:1: /usr/include/stdlib.h:774:12: note: candidate: int abs(int) extern int abs (int __x) __THROW __attribute__ ((__const__)) __wur; ^~~ In file included from /usr/include/c++/6/ext/string_conversions.h:41:0, from /usr/include/c++/6/bits/basic_string.h:5417, from /usr/include/c++/6/string:52, from /usr/include/c++/6/bits/locale_classes.h:40, from /usr/include/c++/6/bits/ios_base.h:41, from /usr/include/c++/6/ios:42, from /usr/include/c++/6/istream:38, from /usr/include/c++/6/fstream:38, from user.cpp:1: /usr/include/c++/6/cstdlib:180:3: note: candidate: long long int std::abs(long long int) abs(long long __x) { return __builtin_llabs (__x); } ^~~ /usr/include/c++/6/cstdlib:172:3: note: candidate: long int std::abs(long int) abs(long __i) { return __builtin_labs(__i); } ^~~