C++ How to convert a vector of size 4 into a 32 bit float

C++ How to convert a vector<uint8_t> of size 4 into a 32 bit float

What is the fastest way to convert a vector of size 4 into a 32 bit float?

My failed attempt:

static bool vec2float32(std::vector<uint8_t> bytes, float &result)
{
if(bytes.size() != 4) return false;
uint8_t sign = (bytes.at(0) & 0x10000000); //will be 1 or 0
uint8_t exponent = (bytes.at(0) & 0x01111111);
uint16_t mantissa = (bytes.at(1) << (2*8)) + (bytes.at(2) << (1*8)) + (bytes.at(3) << (0*8));

result = (2^(exponent - 127)) * mantissa;
if(sign == 1) result = result * -1;
return true;
}


memcpy, all major compilers handle it optimally. Btw, you have bugs in the 0xXXX constants. You used binary, but 0x means hexadecimal.
– geza
Jun 29 at 9:42

^ is bitwise-or, not exponentiation.
– aschepler
Jun 29 at 12:02

^

1 Answer
1

From the vector you can get a pointer to the first byte. If the bytes are already in the correct order, then you can copy the bytes directly into a float variable.

float

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