* Adding 'count_elements' method.
* Actually reporting errors.
* removing white space.
* Removing white space again.
* Adding an extra example.
* Prettier.
* Making the functionality more error-proof.
* Avoiding exceptions.
* Various fixes including extending count_elements to value types.
* Various fixes.
* Minor fixes.
* Correcting comment.
* Trimming white spaces.
To avoid using data belonging to a temporary, the parse functions are ref qualified to get a compile error if used on an rvalue. See https://github.com/simdjson/simdjson/issues/696
Compilation tests are also added, to make sure bad usage fails to compile.
Reviewed by jkeiser.