Strange C ++ pattern to reduce compilation time

Question

I found a template in the OpenSource code of the Tizen Project that can reduce the compilation time of the project. It is used in many places in the project.

As an example, I chose class names ClientSubmoduleSupport. It is short. Here are their sources: client_submode_support.h, client_submode_support.cpp.

As you can see client_submode_support.h, the class that does the work for is defined ClientSubmoduleSupportand client_submode_support.cppexists .ClientSubmoduleSupportImplementationClientSubmoduleSupport

Do you know this model? I am curious about the pros and cons of this approach.

Answer 1

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#ifndef FOO_H
#define FOO_H

struct Foo* foo_create(void);
void foo_destroy(struct Foo* foo);
void foo_do_something(struct Foo* foo);

#endif

// Foo.c:
#include "Foo.h"

struct Foo 
{
    // ...
};

struct Foo* foo_create(void)
{
    return malloc(sizeof(struct Foo));
}

void foo_destroy(struct Foo* foo)
{
    free(foo);
}

void foo_do_something(struct Foo* foo)
{
    // Do something with foo state.
}

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Answer 3

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Answer 4

Using this template to reduce compilation time is widely discussed in J. Lakos. "Large-scale software design in C ++" (Addison-Wesley, 1996).

Herb Sutter is also discussed on the merits of this approach here .