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     28 
     29 /// \file utils/noncopyable.hpp
     30 /// Provides the utils::noncopyable class.
     31 ///
     32 /// The class is provided as a separate module on its own to minimize
     33 /// header-inclusion side-effects.
     34 
     35 #if !defined(UTILS_NONCOPYABLE_HPP)
     36 #define UTILS_NONCOPYABLE_HPP
     37 
     38 
     39 namespace utils {
     40 
     41 
     42 /// Forbids copying a class at compile-time.
     43 ///
     44 /// Inheriting from this class delivers a private copy constructor and an
     45 /// assignment operator that effectively forbid copying the class during
     46 /// compilation.
     47 ///
     48 /// Always use private inheritance.
     49 class noncopyable {
     50     /// Data placeholder.
     51     ///
     52     /// The class cannot be empty; otherwise we get ABI-stability warnings
     53     /// during the build, which will break it due to strict checking.
     54     int _noncopyable_dummy;
     55 
     56     /// Private copy constructor to deny copying of subclasses.
     57     noncopyable(const noncopyable&);
     58 
     59     /// Private assignment constructor to deny copying of subclasses.
     60     noncopyable& operator=(const noncopyable&);
     61 
     62 protected:
     63     // Explicitly needed to provide some non-private functions.  Otherwise
     64     // we also get some warnings during the build.
     65     noncopyable(void) {}
     66     ~noncopyable(void) {}
     67 };
     68 
     69 
     70 }  // namespace utils
     71 
     72 
     73 #endif  // !defined(UTILS_NONCOPYABLE_HPP)
     74