浮动右移

Question

I have float var like that

float f = 0b 00000000 11110001 00000000 00000000 

I want to take 1st(not 0st) byte to char variable. I can't do << and >>. how can i do that?

Answer 1

There is generally little point messing with the binary representation of floating point values. Any you'll try will not be portable. However, generally, these two work:

char c(reinterpret_cast<char*>(&f)[1]);
union {
    float f;
    char  c[sizeof(float)];
} u = { f };
u.c[1];

Answer 2

char bla;
bla = *((char *) &f + 1)

Also remember that with endianness, on little endian systems what you may actually want is byte 2 (assuming you count your byte from 0 to 3). In that case you would change the + 1 with + 2 in the code above.