C++ Tips

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Printing uint8_t with iostream

When printing a uint8_t with iostream it is normally treated as a char and thus interpreted as ASCII. To avoid this, either add a unary plus (+) in front of the variable or simply cast it to unsigned int. 
class ptp_clock_identity
{
public:
  uint8_t id[8];
};

static inline std::ostream& operator<<(std::ostream& os, const class ptp_clock_identity& pi)
{
  // need the static cast here, otherwise the uint8_t is printed as ASCII
  os << std::hex << std::setw(2)
     << static_cast<unsigned int>(pi.id[0])
     << static_cast<unsigned int>(pi.id[1])
     << static_cast<unsigned int>(pi.id[2])
     << "."
     << static_cast<unsigned int>(pi.id[3])
     << static_cast<unsigned int>(pi.id[4])
     << "."
     << static_cast<unsigned int>(pi.id[5])
     << static_cast<unsigned int>(pi.id[6])
     << static_cast<unsigned int>(pi.id[7]);
    return os;
}

Solving Compiler Errors

std::unique_ptr causes error: invalid application of ‘sizeof’ to incomplete type ‘XXX’

This happens only if you haven't implemented a destructor in your cpp file. Thus a default destructor or a inline destructor in your header will cause this error. Source: ortogonal.github.io