Question

similar to iostream.h ,conio.h , …

Answer 1

The standard library is generally all templates. You can just open up the desired header and see how it’s implemented^†. Note it’s not <iostream.h>, it’s <iostream>; the C++ standard library does not have .h extensions. C libraries like <string.h> can be included as <cstring> (though that generally just includes string.h)

That said, the run-time library (stuff like the C library, not-template-stuff) is compiled. You can search around your compiler install directory to find the source-code to the run-time library.

Why? If just to look, there you go. But it’s a terrible way to try to learn, as the code may have non-standard extensions specific to the compiler, and most implementations are just generally ugly to read.

If you have a specific question about the inner-workings of a function, feel free to start a new question and ask how it works.

_{† I should mention that you may, on the off chance, have a compiler that supports export. This would mean it’s entirely possible they have templated code also compiled; this is highly unlikely though. Just should be mentioned for completeness.}