Benjamin Kosnik - Re: user-defined types and basic_string (original) (raw)

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• From: Benjamin Kosnik
• To: Gabriel Dos Reis
• Cc: libstdc++ at gcc dot gnu dot org
• Date: Fri, 23 Aug 2002 11🔞14 -0700
• Subject: Re: user-defined types and basic_string
• Organization: Red Hat / San Francisco
• References: <200208231731.g7NHV7Q02241@fillmore.constant.com><m37kihv4eq.fsf@soliton.integrable-solutions.net>

User-defined constructors are not permitted in PODs. I think we don't really need the conversion function. To the above should just read

struct character { unsigned short value; };

Or, I think we could just put in a template surrogate for fundamental types:

template struct character { T value; };

along with the two functions:

template inline bool operator==(character lhs, character rhs) { return lhs.value == rhs.value; }

template inline bool operator<(character lhs, character rhs) { return lhs.value < rhs.value; }

Cool. I stand corrected.

| // NB: this type should be bigger than char_type, so as to | // properly hold EOF values in addition to the full range of | // char_type values. | typedef unsigned long int_type;

This makes the assumption that range(unsigned long) is a strict superset of range(unsigned short). If we were going to assume that, why not just use "int" as int_type?

Could do. (Unsigned int though if value_type == unsigned short, oui?)

It seems int_type is one of the points where the generic templates start to fall down...

From your yesterday mail, I thought you were talking of a generic way to define customization points of char_traits for users.

Actually, I'm not convinced that we should make a big deal about defining a specialization for std::char_traits<>. Defining such a specialization just amonts to define a trait class in one's own namespace, but then there is no need to wrap the fundamental types in a struct. Thoughts?

I'm not quite sure I follow you. Can you give examples in C++?

-benjamin

• Follow-Ups:
  • Re: user-defined types and basic_string
    * From: Matt Austern
  • Re: user-defined types and basic_string
    * From: Gabriel Dos Reis
• References:
  • user-defined types and basic_string
    * From: Benjamin Kosnik
  • Re: user-defined types and basic_string
    * From: Gabriel Dos Reis