Delegate `int` constructor to `double`.
`to_boolean` should also be available for all content types.
Add an extra namespace for implementation.
Refactoring decode.
Fixed parse issues.
Optimized stringify().
Use pointer in array/object.
Split implementation into files of specific types.
Use string iterator directly.
Add decode class back for better iterator manipulation.
Return object instead of pointer.
Declare globals (solo) inside classes.
Move trivial methods inline.
Create data instead of whole json, for `emplace`.