On Sunday, 19 October 2014 at 03:14:26 UTC, Charles Hixson via
Digitalmars-d-learn wrote:
What is the best way to convert from a part of a ubyte[] to a
float?
I've tried converting the ubyte[] into a uint, but neither
casting the uint to a float nor to!float work.
I suppose I could use a "trick record" union, but that seems
inelegant. If I use pointers, the alignment may
(unpredictably) not be proper (whatever that means these days).
Is this what you're after?
http://dlang.org/phobos/std_bitmanip.html#.peek
http://dlang.org/phobos/std_bitmanip.html#.read
http://dlang.org/phobos/std_bitmanip.html#.write
These accept indices, or you can just slice the ubyte[] to the
part you need.
---
import std.stdio;
import std.bitmanip;
import std.system;
void main()
{
// UBYTE[] to FLOAT
//
// 6.5535000E+004 00-FF-7F-47
ubyte[] ubval = [0, 0xff, 0x7f, 0x47];
auto fval = ubval.peek!(float, Endian.littleEndian);
writefln("%s as float: %s", ubval, fval);
writefln("%s as float: %s", ubval, ubval.read!(float,
Endian.littleEndian));
// 16383.8 00-FF-7F-46
ubval = [0, 0xff, 0x7f, 0x46];
fval = ubval.peek!(float, Endian.littleEndian);
writefln("%s as float: %s", ubval, fval);
writefln("%s as float: %s", ubval, ubval.read!(float,
Endian.littleEndian));
// FLOAT to UBYTE[]
ubval = [0, 0, 0, 0];
std.bitmanip.write!(float, Endian.littleEndian)(ubval,
65535.0f, 0);
writefln("%s as ubyte[]: %s", fval, ubval);
ubval = [0, 0, 0, 0];
std.bitmanip.write!(float, Endian.littleEndian)(ubval, fval,
0);
writefln("%s as ubyte[]: %s", fval, ubval);
}
---
