C Headers in C : Global Namespace or std:: Namespace?

Using C Headers in C : Global Namespace or std:: Namespace?

In C , the use of C headers is possible with minor modifications to their names, for example, stdio.h becomes cstdio. This raises the question of whether it is preferable to use functions from the std:: namespace or the global namespace when calling C functions in C code.

Explanation:

According to the C 11 Standard, all C header names in the form of "name.h" are automatically placed in the global namespace for compatibility with the C standard library. However, the Standard does not specify whether these names are first declared or defined within the std:: namespace and then injected into the global namespace or vice versa.

Recommendation:

Based on the Standard's recommendations, it is suggested to prefer including the "cname" headers (e.g., cstdio) and using declarations and definitions from the std:: namespace for the following reasons:

• Deprecation of "name.h" Headers: The "name.h" headers have been deprecated and may be removed in future revisions.
• Improved Code Clarity: Using the std:: namespace helps distinguish between C and C declarations, enhancing code readability.

Example:

A preferred approach would be:

#include <cstdio>

int main() {
    std::printf("Hello world\n");
}

Conclusion:

While it is possible to call C functions using either the global namespace or the std:: namespace, it is more advisable to follow the suggestions of the C Standard and prefer using cname headers with std:: namespace declarations and definitions.

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