C++ std::audio library

theory and definitions:

    sample:
    a single sample of audio data.
    can be represented by a signed integer, float or double.
    must pass the following test to be a valid sample type:
        ((std::is_integral<T>::value && std::is_signed<T>::value) || std::is_floating_point<T>::value) == true
    or could be constrained by:
         std::is_arithmetic<T>::value==true
     if unsigned samples are allowed/desired

    frame:
    a collection of 0-N samples
    each sample represents an individual channel of audio data
    indexable as an array
    (should N be runtime or compile time?)

    buffer:
    a collection of 0-N frames
    indexable as an array
    (should N be runtime or compile time?)
    ideally maintains a continous piece of memory to house its frames

    device /interface:
    a device recognized by the system as being capable of reading and writing audio data
    can be polled for information regarding the capabilities of the device/interface


    audio callback:
    a function/lambda/functor registered with the library to be called once per buffer interval

    sampling rate: the number of samples per second of audio data

    frame interval: the length of a frame in seconds (1.0/sample_rate)
    buffer interval: the length of a buffer in seconds (frame_interval* buffer_size)