namespaces

问题 I use c++11 while I need some classes from c++17 library. When using boost from which classes were added I wish to do the following: #if __cplusplus < CPP17 using std::any = boost::any; #endif Such alias is not allowed. Also extending the std namespace causes undefined behaviour. I wish my code to look the same regardles of the c++ version. Is there a clear way? 回答1: The clear way is to add a customized name for it. #if __cplusplus < CPP17 using my_any = boost::any; #else using my_any = std:

问题 I use c++11 while I need some classes from c++17 library. When using boost from which classes were added I wish to do the following: #if __cplusplus < CPP17 using std::any = boost::any; #endif Such alias is not allowed. Also extending the std namespace causes undefined behaviour. I wish my code to look the same regardles of the c++ version. Is there a clear way? 回答1: The clear way is to add a customized name for it. #if __cplusplus < CPP17 using my_any = boost::any; #else using my_any = std:

问题 I know I must be doing something wrong here. rank.h #ifndef RANK_H #define RANK_H namespace mmi { int chunk; void rank(int my_rank); } #endif rank.cpp #include "rank.h" namespace mmi { //do something with chunk } main.cpp #include "rank.h" int main() { mmi::chunk = 1; } And the output of compilation; g++ -g -Wall -std=gnu++11 -c -o main.o main.cpp g++ -g -Wall -std=gnu++11 -c -o rank.o rank.cpp mpic++ main.o rank.o -o main rank.o:(.bss+0x0): multiple definition of `mmi::chunk' main.o:(.bss

问题 R beginner here, who really misses Python's import pandas as pd import my_file_which_is_just_a_file_not_a_package as mf out = mf.my_cool_function() I have found a way to implement something similar to the former (assigning an alias to a package), but how to do the latter, i.e. how to assign an alias to an .R file (not a package) you are importing? E.g. you have put some functions you use frequently into a separate .R file, or you are dividing your program into multiple .R files to keep things

问题 R beginner here, who really misses Python's import pandas as pd import my_file_which_is_just_a_file_not_a_package as mf out = mf.my_cool_function() I have found a way to implement something similar to the former (assigning an alias to a package), but how to do the latter, i.e. how to assign an alias to an .R file (not a package) you are importing? E.g. you have put some functions you use frequently into a separate .R file, or you are dividing your program into multiple .R files to keep things

问题 Would it be possible to call a global function from imported function in Python 3? ./folders/folder1/def.py def do_test(): print("++ def.do_test()") global_function_1() print("-- def.do_test()") ./main.py import importlib def global_function_1(): print("doing function 1 thing...") mod = importlib.import_module('folders.folder1.def') mod.do_test() I have the error like this. ++ def.do_test() Traceback (most recent call last): File "C:\src\python\class2\main.py", line 10, in <module> mod.do

问题 Okay so I'm learning to use the new InputActions and I've created a C# scripts using https://prnt.sc/oyaj5l And this is what I got: // GENERATED AUTOMATICALLY FROM 'Assets/PlayerControls.inputactions' using System.Collections; using System.Collections.Generic; using UnityEngine.InputSystem; using UnityEngine.InputSystem.Utilities; public class PlayerControls : IInputActionCollection { private InputActionAsset asset; public PlayerControls() { /// } } But when I try to create an PlayerControls

问题 Okay so I'm learning to use the new InputActions and I've created a C# scripts using https://prnt.sc/oyaj5l And this is what I got: // GENERATED AUTOMATICALLY FROM 'Assets/PlayerControls.inputactions' using System.Collections; using System.Collections.Generic; using UnityEngine.InputSystem; using UnityEngine.InputSystem.Utilities; public class PlayerControls : IInputActionCollection { private InputActionAsset asset; public PlayerControls() { /// } } But when I try to create an PlayerControls

问题 Okay so I'm learning to use the new InputActions and I've created a C# scripts using https://prnt.sc/oyaj5l And this is what I got: // GENERATED AUTOMATICALLY FROM 'Assets/PlayerControls.inputactions' using System.Collections; using System.Collections.Generic; using UnityEngine.InputSystem; using UnityEngine.InputSystem.Utilities; public class PlayerControls : IInputActionCollection { private InputActionAsset asset; public PlayerControls() { /// } } But when I try to create an PlayerControls

问题 Is there any way to call a function that is inside of a namespace without declaring the class inside c#. For Example, if I had 2 methods that are the exact same and should be used in all of my C# projects, is there any way to just take those functions and make it into a dll and just say 'Using myTwoMethods' on top and start using the methods without declaring the class? Right now, I do: MyClass.MyMethod(); I want to do: MyMethod(); Thanks, Rohit 回答1: You can't declare methods outside of a