Not sure which solution is fastest without a benchmark, but an alternative is using the built in copy: cpy := make([]T, len(orig)) copy(cpy, orig) From the documentation: func copy(dst, src []Type) int The copy built-in function copies elements from a source slice into a destination slice. (As a special case, it also will copy bytes … Read more
Deep Copy Your example is not a deep copy as discussed on StackOverflow. Getting a true deep copy of an object would often require NSKeyedArchiver Swift and copying The NSCopying protocol is the Objective-C way of providing object copies because everything was a pointer and you needed a way of managing the generation of copies … Read more
I think the deep copy need not involve byte[]. Try the following: public static ByteBuffer clone(ByteBuffer original) { ByteBuffer clone = ByteBuffer.allocate(original.capacity()); original.rewind();//copy from the beginning clone.put(original); original.rewind(); clone.flip(); return clone; }
If your object is “small” and contains exclusively serializable properties, a simple deepCopy hack using JSON serialization should be OK. But, if your object is large, you could run into problems. And if it contains unserializable properties, those’ll go missing: var o = { a: 1, b: 2, sum: function() { return a + b; … Read more
You should not be confused by (1) and (2). In general, Python tries to include sensible fall-backs for missing methods. (For instance, it is enough to define __getitem__ in order to have an iterable class, but it may be more efficient to also implement __iter__. Similar for operations like __add__, with optional __iadd__ etc.) __deepcopy__ … Read more
I think, that using assignment is not the best way of matrix copying. If you want new full copy of the matrix, use: Mat a=b.clone(); If you want copy matrix for replace the data from another matrix (for avoid memory reallocation) use: Mat a(b.size(),b.type()); b.copyTo(a); When you assign one matrix to another, the counter of … Read more
Problem is, pickle+unpickle can be faster (in the C implementation) because it’s less general than deepcopy: many objects can be deepcopied but not pickled. Suppose for example that your class A were changed to…: class A(object): class B(object): pass def __init__(self): self.b = self.B() now, copy1 still works fine (A’s complexity slows it downs but … Read more
You have two main options: Use JSON.stringify and JSON.parse: var copy = JSON.parse(JSON.stringify(original)); But I’ve never liked that. A round-trip through text is inefficient at best, and it won’t handle functions or Date, RegExp, undefined, etc. values correctly unless you write a replacer and a reviver. Use a recursive function, something like this: var toString … Read more
In Python3: import types import functools def copy_func(f): “””Based on http://stackoverflow.com/a/6528148/190597 (Glenn Maynard)””” g = types.FunctionType(f.__code__, f.__globals__, name=f.__name__, argdefs=f.__defaults__, closure=f.__closure__) g = functools.update_wrapper(g, f) g.__kwdefaults__ = f.__kwdefaults__ return g def f(arg1, arg2, arg3, kwarg1=”FOO”, *args, kwarg2=”BAR”, kwarg3=”BAZ”): return (arg1, arg2, arg3, args, kwarg1, kwarg2, kwarg3) f.cache = [1,2,3] g = copy_func(f) print(f(1,2,3,4,5)) print(g(1,2,3,4,5)) print(g.cache) assert … Read more
You may get some good use out of the Amoeba gem for ActiveRecord 3.2. It supports easy and automatic recursive duplication of has_one, has_many and has_and_belongs_to_many associations, field preprocessing and a highly flexible and powerful configuration DSL that can be applied both to the model and on the fly. be sure to check out the … Read more