If T is an unsigned integer type, these methods are guaranteed to
overflow unless the result is actually real, so we should disallow
them for the same reason that Neg was removed from these types.
Signed-off-by: Anders Kaseorg <andersk@mit.edu>
Along the way, this commit also rationalizes the traits a bit more.
Moving to stable required vendoring a couple of minor things (notably,
radix formatting).
This commit brings in a load of unstable and/or deprecated traits from
the `std::num` module. These traits provide for some degree of generic
programming over numeric types. They are not stable in `std` mostly
because we want more time to iterate on their design. Moving them to the
`num` crate allows existing code to keep using this functionality as we
do so.
Closes#74
The code was performing an extra squaring of the base, which might
trigger an arithmetic overflow that doesn't matter to the result. Now
this squaring is only attempted when enough exp remains to need it.
A new doctest tries pow(6u8, 3), where an extra square would exceed 256.
`str::from_utf8` changed its return type to `Result`, but
`num::FromStrRadix::from_str_radix` still returns an `Option`. In this case
discarding the `Err` variant with `ok()` seems fine to me.
Now, arithmetic binary operator traits take operands by value,
but non-copyable types such as `BigUint` should not always moved out when
applying operators.
This commit implements these operators not only for bare structs also
these references.
By-value implementations are forwarded to by-reference implementations
for now. In the future, by-value implementations may be replaced with
more efficient implementations (for example, the implementation that
reuses moved buffers.)