declaration

I'm curious about the benefits/detriments of different constant declaration and definition options in C++. For the longest time, I've just been declaring them at the top of the header file before the class definition: //.h const int MyConst = 10; const string MyStrConst = "String"; class MyClass { ... }; While this pollutes the global namespace (which I know is a bad thing, but have never found a laundry list of reasons why it is bad), the constants will still be scoped to individual translation units, so files that don't include this header won't have access to these constants. But you can

I was snooping through my MSP430 microcontroller's header files, and I ran into this in <setjmp.h> : /* r3 does not have to be saved */ typedef struct { uint32_t __j_pc; /* return address */ uint32_t __j_sp; /* r1 stack pointer */ uint32_t __j_sr; /* r2 status register */ uint32_t __j_r4; uint32_t __j_r5; uint32_t __j_r6; uint32_t __j_r7; uint32_t __j_r8; uint32_t __j_r9; uint32_t __j_r10; uint32_t __j_r11; } jmp_buf[1]; /* size = 20 bytes */ I understand that it declares an anonymous struct and typedef's it to jmp_buf , but I can't figure out what the [1] is for. I know it declares jmp_buf to

I always though that declaring char *c = "line"; was the same as char c[] = "line"; and so I did char **choices = { "New Game", "Continue Game", "Exit" }; Which gives me an incompatible pointer type, where char *choices[] = { "New Game", "Continue Game", "Exit" }; doesn't. Any help on understanding this? Well, they're not the same. It's just easier for most people to think of them as being the same so everyone starts to think that way until they run into a problem like the above :-) I was going to write something long and winded, but then I figured... Someone else must have done this already.

#include<stdio.h> #include<conio.h> int main(){ char i; int c; scanf("%i",&c); scanf("%c",&i);// catch the new line or character introduced before x number printf("%i",i);// value of that character getch(); return(0); } The program will behave in the same way with the next variable declarations instead of the above variable declaration: this: int c; int *x; int i; or this: int *x; int c; int i; And only this way: c variable and a x pointer before the i variable. I know that those last declarations haven't sense, the int i instead of char i , and an added pointer that isn't even needed. But

Lets take this code sample //header struct A { }; struct B { }; struct C { }; extern C c; //code A myfunc(B&b){ A a; return a; } void myfunc(B&b, C&c){} C c; Lets do this line by line starting from the code section. When the compiler sees the first myfunc method it does not care about A or B because its use is internal. Each c++ file will know what it takes in, what it returns. Although there needs to be a name for each of the two overload so how is that chosen and how does the linker know which means what? Next is C c; I once had a bug were the linker wouldnt reconize thus allow me access to

i'm new in c++ programing and need some help to use a thread library with vector library... first I follow this tutorial but the compiler (visual studio 2013) show me errors and I don't know how correct it: first declaration of function void Fractal::calcIterThread(vector<vector<iterc>> &matriz, int desdePos, int hastaPos, int idThread){ ... } in main loop vector<vector<iterc>> res; res.resize(altoPantalla); for (int i = 0; i < altoPantalla; i++){ res[i].resize(anchoPantalla); } int numThreads = 10; vector<thread> workers(numThreads); for (int i = 0; i < numThreads; i++){ //here diferent try