I am reading the book “Exceptional C++” by Herb Sutter, and in that book I have learned about the PIMPL idiom. Basically, the idea is to create a structure for the private objects of a class and dynamically allocate them to decrease the compilation time (and also hide the private implementations in a better manner).
For example:
class X
{
private:
C c;
D d;
} ;
could be changed to:
class X
{
private:
struct XImpl;
XImpl* pImpl;
};
and, in the .cpp file, the definition:
struct X::XImpl
{
C c;
D d;
};
This seems pretty interesting, but I have never seen this kind of approach before, neither in the companies I have worked, nor in open source projects that I’ve seen the source code. So, I am wondering whether this technique is really used in practice.
Should I use it everywhere, or with caution? And is this technique recommended to be used in embedded systems (where the performance is very important)?
