prindex

A simple, lightweight wrapper around C++'s type_info for consistent, cross-compiler usage.

Get the same name() and hash_code() on every (supported) compiler and standard library.

Installation

Prindex is a single-header library. You can download the latest release here. Using prindex requires support of C++11.

Usage

Prindex was designed to be as similar in usage as type_info and type_index. Here is a table of different uses and their alternatives in prindex:

C++ Standard	prindex
typeid(type)	zh::prid<type>() or PRID(type)
typeid(expr)	zh::prid(expr) or PRID(expr)
const std::type_info& ti = typeid(...)	const zh::prinfo& ti = PRID(...)
std::type_index(typeid(...))	zh::prindex(zh::prid(...)) or PRIDX(...)

If you would like to take advantage of the true keyword experience, prindex includes helpful macros, so you can use PRID(type) instead of zh::prid<type>() (same for pridx).

All interfaces of included classes are identical to the corresponding ones in the C++ Standard.

Documentation

All classes and functions described are in namespace zh.

class prinfo

The class prinfo holds implementation-independent information about a type, including the name of the type and means to compare two types for equality or collating order. This is the class returned by the prid operator.

The prinfo class is neither CopyConstructible nor CopyAssignable.

Member functions

• (constructor) [deleted]
  has neither default nor copy constructors
• (destructor) [virtual]
  derived objects are safe to delete through pointer-to-base
• operator= [deleted]
  can not be copy-assigned
• operator==
• operator!=
  checks whether the objects refer to the same type
• before
  checks whether the referred type precedes referred type of another prinfo object in the implementation defined order, i.e. orders the referred types
• hash_code
  returns a value which is identical for the same types
• name
  implementation-independent name of the type

class prindex

The prindex class is a wrapper class around a prinfo object, that can be used as index in associative and unordered associative containers. The relationship with prinfo object is maintained through a pointer, therefore prindex is CopyConstructible and CopyAssignable.

Member functions

• (constructor)
  constructs the object
• (destructor)
  destroys the prindex object
• operator=
  assigns a prindex object
• operator==
• operator!=
• operator<
• operator<=
• operator>
• operator>=
  compares the underlying prinfo objects
• hash_code
  returns hashed code
• name
  returns implementation-independent name of the type, associated with underlying prinfo object

Helper classes

std::hash<prindex>
hash support for prindex

Function/macro prid

template <class T>
inline const prinfo& prid();

template <class T>
inline const prinfo& prid(T&& obj);

#define PRID(...) \
zh::detail::get_prinfo(typeid(__VA_ARGS__))

The prid function returns a const reference to a prid object, holding implementation-independent information about a type or expression passed into it. PRID is a macro that does the same thing.

Function/macro pridx

template <class T>
inline prindex pridx();

template <class T>
inline prindex pridx(T&& obj);

#define PRIDX(...) \
zh::prindex(zh::detail::get_prinfo(typeid(__VA_ARGS__)))

The pridx function returns a prindex object, holding implementation-independent information about a type or expression passed into it. PRIDX is a macro that does the same thing.

License

This project is licenced under the MIT licence. It is free for personal and commercial use.