[boost] max, min, width, precision, promotion and other toys (0/1)

From: Gennaro Prota (gennaro_prota_at_[hidden])
Date: 2003-01-07 19:22:43

Hi everybody,

the attached files contain a bunch of trivial stuff related to
integral types that I need in a lot of situations. Any interest for
inclusion into boost? Here's a summary:

1. max_of<T> and min_of<T>:

    give the maximum and minimum value of any integral type as
    an integral constant expression; care is taken so that

        max_of<T>::value [min_of<T>::value]

    has the same type of the corresponding climits constant (CHAR_MAX,
    INT_MAX, etc.), i.e. the type to which an expression of type T
    is converted according to integral promotions.

2. promotes_to<T>:

    gives the type which the integral type T promotes to

3. has_sign<T>:

    simply defined as

       template <typename T>
       struct has_sign {
          static const bool value = min_of<T>::value < 0;
       };

    Tells whether T is able to represent any negative value,
    regardless of whether the C++ standard calls it a signed
    integral type or not.

4. precision<T>:

    gives the precision of an integral type, which is the
    number of bits it uses to represent values, excluding any
    sign and padding bits.

5. width<T>:

    same as precision, but including any sign bit

6. has_padding<T>:

    says whether T has padding or not.

The file intconst_log2.hpp is just used for the implementation of the
remaining stuff.

Genny.