Function coordToHex

Rapfi/database/dbtypes.cpp:28–31

namespace {

constexpr char coordToHex(int coord)
{
    return coord < 10 ? '0' + coord : 'A' + coord - 10;
}
constexpr int hexToCoord(char hex)
{
    return hex <= '9' ? hex - '0' : hex - 'A' + 10;