As written, NULL isn’t defined in your program. Usually, that’s defined in a standard header file — specifically <cstddef> or <stddef.h>. Since you’re restricted to iostream, if yours doesn’t get NULL implicitly from that header, you can use 0 or, in C++11, nullptr, which is a keyword and doesn’t require a header. (It is not recommended to define NULL yourself. It might work sometimes, but it is technically … Read more
1.Go to Control panel 2.In the Add or Remove Programs dialog box, select the product you want to repair and then click Change/Remove 3.In the Setup wizard, click Next 4.Click Repair 5.Then Modify it by selecting C++ to add it. Note : This work in Window OS only
Are you actually trying to round the number, or just change its displayed precision? For the former (truncating the extra digits): or (rounding up/down as appropriate, per jheriko’s answer) For the latter: where the parameter to setprecision() is the maximum number of digits to show after the decimal point.
Thats a linker problem. Try to change Properties -> Linker -> System -> SubSystem (in Visual Studio). from Windows (/SUBSYSTEM:WINDOWS) to Console (/SUBSYSTEM:CONSOLE) This one helped me
You are overloading << operator as a member function, therefore, the first parameter is implicitly the calling object. You should either overload it as friend function or as a free function. For example: overloading as friend function. However, the canonical way is to overload it as free function. You can find very good information from this post: C++ operator overloading
I think you are confused about how the compiler puts things together. When you use -c flag, i.e. no linking is done, the input is C++ code, and the output is object code. The .o files thus don’t mix with -c, and compiler warns you about that. Symbols from object file are not moved to other object files like that. All object … Read more
Be careful, (x1-x2)^2 will not do an exponent of 2 here. See http://www.cplusplus.com/reference/cmath/pow/. Second, you probably forgot a + in your expression:
This code returns a 2d array.
You have a cyclical dependency. Both files need one another to compile. Try forward-declaring User in group: Group.cpp Then in the Group.cpp file, include User. You can forward declare in the header anytime the object size doesn’t depend on the actual size of the object your forward declaring. In this case, (in Group) you use … Read more
Magic Enum header-only library provides static reflection for enums (to string, from string, iteration) for C++17. For more examples check home repository https://github.com/Neargye/magic_enum. Where is the drawback? This library uses a compiler-specific hack (based on __PRETTY_FUNCTION__ / __FUNCSIG__), which works on Clang >= 5, MSVC >= 15.3 and GCC >= 9. Enum value must be in range [MAGIC_ENUM_RANGE_MIN, MAGIC_ENUM_RANGE_MAX]. By default MAGIC_ENUM_RANGE_MIN … Read more