Only x is a pointer to int; y and z are regular ints. This is one aspect of C declaration syntax that trips some people up. C uses the concept of a declarator, which introduces the name of the thing being declared along with additional type information not provided by the type specifier. In the … Read more
In C, the statement int a; when made at file scope, is a declaration and a tentative definition. You can have as many tentative definitions as you want, as long as they all match each other. If a definition (with an initializer) appears before the end of the translation unit, the variable will be initialized … Read more
The simplest solution is to put a named struct instance as a member in the unnamed one, and put all of the functionality into the named instance. This is probably the only way that is compatible with C++98. #include <iostream> #include <cmath> int main() { struct { struct S { double a; int b; S() … Read more
The link provided by @MichaelHaren appears to provide the root cause. The semicolon (as others have pointed out) is inherited from C. But that doesn’t explain why C used it in the first place. The discussion includes this gem of an example: struct fred { int x; long y; }; main() { return 0; } … Read more
I haven’t done this in a while! Start with foo and go right. float * (*(*foo())[SIZE][SIZE])() foo is a function with no arguments… Can’t go right since there’s a closing parenthesis. Go left: float * (*(* foo())[SIZE][SIZE])() foo is a function with no arguments returning a pointer Can’t go left further, so let’s cross the … Read more
The const modifier is trivial: it modifies what precedes it, unless nothing precedes it. So: char const* buffer; // const modifies char char* const buffer; // const modifies * , etc. Generally, It’s best to avoid the forms where nothing precedes the const, but in practice, you’re going to see them, so you have to … Read more
a, b, c, d, e, g, h, i, j = (True,)*9 f = False
This is really a C question, because this behaviour was inherited directly from C (although it gets much more press in C++ because of the most vexing parse). I suspect the answer (in the context of C, at least) is that this allows you to scope the existence of your function declarations to precisely where … Read more
It is allowed to declare a variable in the control part of a nested block, but in the case of if and while, the variable must be initialized to a numeric or boolean value that will be interpreted as the condition. It cannot be included in a more complex expression! In the particular case you … Read more
Here is a great article about how to read complex declarations in C: http://www.codeproject.com/KB/cpp/complex_declarations.aspx It helped me a lot! Especially – You should read “The right rule” section. Here quote: int * (* (*fp1) (int) ) [10]; This can be interpreted as follows: Start from the variable name ————————– fp1 Nothing to right but ) … Read more