xref: /freebsd/contrib/kyua/utils/noncopyable.hpp (revision b0d29bc47dba79f6f38e67eabadfb4b32ffd9390)

// Copyright 2010 The Kyua Authors.
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/// \file utils/noncopyable.hpp
/// Provides the utils::noncopyable class.
///
/// The class is provided as a separate module on its own to minimize
/// header-inclusion side-effects.

#if !defined(UTILS_NONCOPYABLE_HPP)
#define UTILS_NONCOPYABLE_HPP


namespace utils {


/// Forbids copying a class at compile-time.
///
/// Inheriting from this class delivers a private copy constructor and an
/// assignment operator that effectively forbid copying the class during
/// compilation.
///
/// Always use private inheritance.
class noncopyable {
    /// Data placeholder.
    ///
    /// The class cannot be empty; otherwise we get ABI-stability warnings
    /// during the build, which will break it due to strict checking.
    int _noncopyable_dummy;

    /// Private copy constructor to deny copying of subclasses.
    noncopyable(const noncopyable&);

    /// Private assignment constructor to deny copying of subclasses.
    ///
    /// \return A reference to the object.
    noncopyable& operator=(const noncopyable&);

protected:
    // Explicitly needed to provide some non-private functions.  Otherwise
    // we also get some warnings during the build.
    noncopyable(void) {}
    ~noncopyable(void) {}
};


}  // namespace utils


#endif  // !defined(UTILS_NONCOPYABLE_HPP)