Question

I’m trying to make a C++ class using the Code::Blocks IDE and there is a field called “Guard block.” I’ve done a search and haven’t been able to find any useful information. What is this field for? Thanks.

Answer 1

Guard blocks are used to protect against the inclusion of a header file multiple times by the same compilation unit (c++ file). They look something like this:

// Foo.h
#ifndef INCLUDE_FILE_NAME_HERE_H_
#define INCLUDE_FILE_NAME_HERE_H_

class Foo
{
};


#endif

If you include the same file multiple files, you will end up with multiple definition error. Using of include guards isn’t necessary in small projects but becomes critical in any medium to large sized projects. I use it routinely on any header files I write.