You need not fo any conversion because int and char are integral types. It is only visual representation of a character provided by output functions for objects of type char.
So you can write simply
int a = 87;
char b = a;
or
std:;cout << ( char )a << std::endl;
or
std:;cout << static_cast<char>( a ) << std::endl;
or
std:;cout << b << std::endl;