def pyx_is_cplus(path):
    """
    Inspect a Cython source file (.pyx) and look for comment line like:

    # distutils: language = c++

    Returns True if such a file is present in the file, else False.
    """
    for line in open(path, 'rt'):
        if line.startswith('#') and '=' in line:
            splitted = line.split('=')
            if len(splitted) != 2:
                continue
            lhs, rhs = splitted
            if lhs.strip().split()[-1].lower() == 'language' and \
               rhs.strip().split()[0].lower() == 'c++':
                    return True
    return False