ambiguous call to overloaded function, C++ (vc++)

ambiguous call to overloaded function

Language: Layout:

Show compiler warnings [ + ] Compiler args [ + ] Show input
Compilation time: 1,84 sec, absolute service time: 1,87 sec

Error(s):

source_file.cpp(18): error C2666: 'foo': 2 overloads have similar conversions
source_file.cpp(5): note: could be 'void foo(const A *,int)'
source_file.cpp(4): note: or       'void foo(A *,std::string)'
source_file.cpp(18): note: while trying to match the argument list '(A *, int)'
source_file.cpp(18): note: note: qualification adjustment (const/volatile) may be causing the ambiguity
Microsoft (R) C/C++ Optimizing Compiler Version 19.00.23506 for x64