How Can I Customize C Standard Stream Objects Without Introducing Risks?

C Standard Library: Customizing Standard Stream Objects

In C , the standard streams cout, cerr, cin, and endl can be cumbersome to use with constant std:: prefixes. To alleviate this issue, one might consider creating custom wrappers with shorter names.

Example with STLWrapper

One possible approach is exemplified by the STLWrapper library:

• STLWrapper.h defines external references to the standard stream objects with shorter names:

  extern std::ostream& Cout;
  extern std::ostream& Cerr;
  extern std::istream& Cin;
  extern std::string&  Endl;

• STLWrapper.cpp provides the actual definitions for these references:

  std::ostream& Cout = std::cout;
  std::ostream& Cerr = std::cerr;
  std::istream& Cerr = std::cin;
  std::string _EndlStr("\n");
  std::string& Endl = _EndlStr;

While this approach is functionally correct, it raises some concerns:

Overloading Risks

Using shorter names for standard objects increases the risk of name collisions with user-defined identifiers. If your code defines its own Cout or Endl, this could inadvertently override the references to the standard streams.

Readability

While shortening prefixes may seem convenient, it can actually reduce code readability. The std:: prefixes provide explicit context for standard library objects, making it easier to trace their use and identify potential issues.

Alternatives to Wrappers

Instead of using wrappers, consider the following alternatives:

• Using function-scoped using declarations within blocks: This limits the scope of using statements to specific code blocks, mitigating the risk of name conflicts.
• Remembering that typing "std::" is not a significant burden: The time spent typing the prefix is minimal compared to the time required to understand and debug your code.
• Recognizing the clarity benefits of std:: prefixes: They help identify standard library objects and distinguish them from user-defined identifiers.

Conclusion

While customizing standard stream objects may seem appealing initially, it's important to consider the potential trade-offs. Overloading risks, reduced readability, and the lack of significant benefits make alternative approaches more advisable.

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