def add(self, elem, replace=False):
        """Add a requirement.

        :param elem: a string or :class:`Requirement` instance.
        :param replace: if `True`, packages in the set with the same name will
            be removed first.
        """
        if isinstance(elem, text_type):
            elem = Requirement.coerce(elem)
        if replace and elem in self:
            self.remove(elem)
        super(Requirements, self).add(elem)
def test_ccode_inline_function():
    x = symbols('x')
    g = implemented_function('g', Lambda(x, 2*x))
    assert ccode(g(x)) == "2*x"
    g = implemented_function('g', Lambda(x, 2*x/Catalan))
    assert ccode(
        g(x)) == "double const Catalan = %s;\n2*x/Catalan" % Catalan.n()
    A = IndexedBase('A')
    i = Idx('i', symbols('n', integer=True))
    g = implemented_function('g', Lambda(x, x*(1 + x)*(2 + x)))
    assert ccode(g(A[i]), assign_to=A[i]) == (
        "for (int i=0; i<n; i++){\n"
        "   A[i] = (A[i] + 1)*(A[i] + 2)*A[i];\n"
        "}"
    )