Use take_mut instead of a bespoke unsafe block with mem::replace

[Shnatsel]

mem::uninitialized is getting deprecated because it's impossible to use it safely in generic code.

On the other hand, take_mut has been reviewed by the Unsafe Code Guidelines WG and has been found to be sound.

[codecov-io]

Codecov Report

Merging #37 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master      #37   +/-   ##
=======================================
  Coverage   91.46%   91.46%           
=======================================
  Files          14       14           
  Lines        1301     1301           
=======================================
  Hits         1190     1190           
  Misses        111      111

Impacted Files	Coverage Δ
src/lib.rs	100% <ø> (ø)	⬆️

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[Shnatsel]

FWIW this borrow-checks but I have not tested this

[sile]

LGTM.

mem::uninitialized is getting deprecated because it's impossible to use it safely in generic code.

I see. Thank you for letting me know.