  the expression's return type. The composite operator templates only list
    what other templates they use. The supplied operations and requirements
    of the composite operator templates can be inferred from the operations
    and requirements of the listed components.</p>

    <h3><a name="smpl_oprs">Simple Arithmetic Operators</a></h3>

    <p>These templates are "simple" since they provide operators based on a
    single operation the base type has to provide. They have an additional
    optional tem