Klarre

Why do some people write their function implementations in the header files?
I can't see any good reason doing that. I think the header files should just be used as a list of the member functions in the class, so you can easily see which functions that are available.

Is there anyone out there who can tell me why this "java style" coding is used by some people?

Ancient Dragon

I put only in-line functions/methods in header files. And inline functions/methods are only one or two statements.

Templates are different -- most templates are implemented in header files because the data type is unknown when the template is written so its not really possible to put the code into *.cpp files.

uman

unless you use "export"

but most compilers don't have that.

mitakeet

Some compilers will troll through .cpp files looking for things to inline (Intel's compiler actually trolls through the binaries), but if you want maximum portablity, you will put in-linable code (and templates) in headers.

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grumpy

Apart from usage of templates (few compilers support export, so the implementation has to be in the header), the most common reasons (in my experience) to put a file implementation in a header are;

1) they want the function to be inline. The compiler can potentially squeeze a bit more performance by inlining the function. YMMV, as the compiler can still decide not to inline a function (and the benefits are also compiler dependent). Simpler functions have most chance of being inlined.

2) laziness - it is easier to create one file rather than two for the same thing. If you don't care about maintainability, recompile times, etc etc.

Klarre

So this means; put all inline and template code in header files, and anything else in cpp files.

/Thanks

mitakeet

What this means is it is a convention where you put the code, though for most compilers if you want the chance for in-lining it must be in the header.

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Free code: http://sol-biotech.com/code/.

It is not that old programmers are any smarter or code better, it is just that they have made the same stupid mistake so many times that it is second nature to fix it.
--Mitakeet

The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man.
--George Bernard Shaw

nnxion

How would header files make recompile times faster? The compiler is going to compile both aint it? So accessing a header file would even make it slower, this would be very unnoticable though.

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DaWei

Precompiled headers.

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nnxion

Aww yeah never really worked with them, maybe because I don't recompile all that often .

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