Summarizing what others have said:
Advantages of boost::noncopyable over private copy methods:
- It is more explicit and descriptive in the intent. Using private copy functions is an idiom that takes longer to spot than
noncopyable.
- It is less code / less typing / less clutter / less room for error (the easiest would be accidentally providing an implementation).
- It embeds meaning right in the type's metadata, similar to a C# attribute. You can now write a function which accepts only objects which are noncopyable.
- It potentially catches errors earlier in the build process. The error will be presented at compile-time rather than link-time, in the case that the class itself or friends of the class are doing the erroneous copying.
- (almost the same as #4) Prevents the class itself or friends of the class from calling the private copy methods.
Advantages of private copy methods over boost::noncopyable:
- No boost dependency