Function Premultiplied.isValidAlpha
Reports whether alpha is a usable opacity from 0 through 1.
bool isValidAlpha() const pure nothrow @nogc @property @safe;
Returns false for values below 0, above 1, NaN, and infinities.
The representation does not clamp invalid alpha values.
Example
const value = Premultiplied!LinearSRgbf(
LinearSRgbf(0.1f, 0.2f, 0.4f),
0.5f
);
assert(value .isValidAlpha);
}