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mili / ArithUtils


This minimalistic library provides some arithmetic manipulation utilities.


This library provides: * bool in_range(T value, T min, T max): returns true if value is in the range [min, max] * bchain<T>: a class for chaining boolean conditions. * Randomizer<T>: a class to produce random numbers. * FirstTimeFlag: a class that values initially true, and false after it's evaluated. * maximize<T>(T& m, T value): sets m to value if the latter is greater than the former, ensuring to set m to the maximum. Returns m. * minimize(): ditto maximize but with minimum. * square(T value): returns value^2. * bool implies(bool p, bool q): returns p=>q

The bchain class

The bchain class (Boolean Chain) is meant to chain boolean operations, such as

    value1 < value2 <= value3 ...

In order to perform such operations, use bchain as follows:

    bchain(value1) < value2 <= value3

You can build a bchain from the first (or second) value, then chain the comparisons, and put all that into an if, while, etc., or even a boolean variable.

A more complete example:

    if (4 <= bchain(value) <= 5)

If you want to use the same value several times, you can declare a bchain once as a variable: _bchain<T>(value) variable;.

The Randomizer class

This class is a standalone random number generators (meaning that may exist several instances, each one having its own seed). The class is constructed with the desired range in which the random numbers will be generated:

   Randomizer<T>(T min, T max);

It also provides the get method to get the next random number:

   Randomizer<float> r(0.0f, 1.0f);
   float number = r.get();

Internally, the class has a specialization for integral types and for floating point types for better results.

The FirstTimeFlag class

This class is useful for iterations, when something special has to be done the first time. An instance of this class can be evaluated in a condition (i.e. in an if), and automagically is self-set to false afterwards.

For example:

   FirstTimeFlag first_iteration;

   while (something)

      if (first_iteration)