Take for example the definition of floor(), how would an IDE or documentation generator see which types are supported? This is just imperative code which is executed at compile time and at least to me it is not obvious how to interpret it when generating the documentation. On the other hand in Rust it is almost always easy to see which types can be used where.

    pub fn floor(x: anytype) @TypeOf(x) {
        const T = @TypeOf(x);
        return switch (T) {
            f16 => floor16(x),
            f32 => floor32(x),
            f64 => floor64(x),
            f128 => floor128(x),
            else => @compileError("floor not implemented for " ++ @typeName(T)),
        };
    }