let's say that i have precomputed some `float`-typed tables, and now i want
to use 'em in my code. for example, a table for Lagrange series. the table
itself is like 10 numbers, but the code calculating it rather big, and it
depends of architecture (so it can yield different results on different
arch). yet i want the same IEEE numbers everywhere.
the code problem is that i really can't express *exactly* *the* *same* IEEE float
with D. let me illustrate this.
one of my calculated values is `-0.166667`, which has bit-pattern of 0xBE2AAAB7.
now, let's say i want to use this number in my code:
float v = -0.166667f;
writefln("%f 0x%08X", v, *cast(uint*)&v);
oooops. "-0.166667 0xBE2AAAC1". it's not the same! (and yes, it matters).
and this means that i can't inline my calculated values! each time i want
to get floating value with a known bit-pattern, i have to store it as uint,
and resort to ugly hack: `*cast(immutable(float)*)(&mytable[2])`.
and i can't do this trick in CTFE, as such pointer tricks aren't permitted.
i tried different workarounds, but they're all ugly. it would be very nice
to have a way to define IEEE floating point numbers as bit-patterns in the
language itself. what do you think?
yes, i know that floating numbers has to be loaded from memory anyway, so
my trick is not really worse than specifying the constant directly. but it
is still dirty trick, and i cannot use it in @safe code too, so i have to
mark my code as @trusted, which is not the same at all. there probably may
be other trick such this for @safe code, but... you got the idea, i think.
