MWX_APIRET

API return value class that wraps 32-bit type. MSB (bit31) is a flag for failure or success. bit0..30 is used to store the return value.

class MWX_APIRET {
	uint32_t _code;
public:
	MWX_APIRET() : _code(0) {}
	MWX_APIRET(bool b) {
	  _code = b ? 0x80000000 : 0;
  }
	MWX_APIRET(bool b, uint32_t val) {
		_code = (b ? 0x80000000 : 0) + (val & 0x7fffffff);
	}
	inline bool is_success() const { return ((_code & 0x80000000) != 0); }
	inline bool is_fail() const { return ((_code & 0x80000000) == 0); }
	inline uint32_t get_value() const { return _code & 0x7fffffff; }
	inline operator uint32_t() const { return get_value(); }
	inline operator bool() const { return is_success(); }
};

constructor

MWX_APIRET()
MWX_APIRET(bool b)
MWX_APIRET(bool b, uint32_t val)

The default constructor is constructed with a combination of false and 0.

It can also be explicitly constructed with bool and uint32_t types as parameters.

Since the constructor of type bool is implemented, you can use true/false as follows.

MWX_APIRET myfunc() {
  if (...) return true;
  else false;
}

Methods

is_success(), operator bool()

inline bool is_success() 
inline operator bool()

Return true if 1 is set in MSB.

inline bool is_fail()

Return true if MSB is 0.

inline uint32_t get_value()
inline operator uint32_t()

Obtain the value part of bit0..30.