Create main.cpp

this program works, but it won't work if execute L8//Rectangle r();
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||=== Build: Debug in Rectangle (compiler: GNU GCC Compiler) ===|
||warning: command line option "-Wmissing-declarations" is valid for C/ObjC but not for C++|
||warning: command line option "-Wmain" is valid for C/ObjC but not for C++|
C:\Users\Tim\Desktop\codeblock\Rectangle\main.cpp||In function `int main()':|
C:\Users\Tim\Desktop\codeblock\Rectangle\main.cpp|13|error: request for member `GetHeight' in `r', which is of non-class type `Rectangle ()()'|
||=== Build failed: 1 error(s), 2 warning(s) (0 minute(s), 0 second(s)) ===|
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Why not "0" instead?(As discussion last night,"Rectangle r()" means "Rectangle(int x=0,int y=0,int h=0,int w=0)" )