compiler-warnings

boost::mutex::scoped_lock is a handy RAII wrapper around locking a mutex. I use a similar technique for something else: a RAII wrapper around asking a data interface to detach from/re-attach to a serial device. What I can't figure out, though, is why in the code below only my object mst — whose instantiation and destruction do have side effects — causes g++ to emit an "unused variable" warning error whereas l manages to remain silent. Do you know? Can you tell me? [generic@sentinel ~]$ cat test.cpp #include <boost/shared_ptr.hpp> #include <boost/thread/mutex.hpp> #include <iostream> struct

This question is not bound to any specific compiler warning, the following is just an example. Currently when I want a loop that checks an exit condition inside: while( true ) { doSomething(); if( condition() ) { break; } doSomethingElse(); } I can't just write that in Visual C++ - it will emit a C4127 conditional expression is constant warning. The compiler will wave it in my face although it's quite obvious that while(true) can't have been written accidentially. Suppose I want code that compiles without warnings. There're workarounds at my service. Workaround one is to use for(;;) but it

This question already has an answer here: Returning an address of local variable behaviour [duplicate] 2 answers This is a portion of a homework assignment. I am trying to read and return a single line of a file in my method getLine. char *getLine(FILE *input) { char line[30]; if(fgets(line, sizeof(line), input)!=NULL) { return line; }else{ return NULL; } } This would seem to work from what I have been taught regarding pointers, however I am unable to remove the warning message warning: function returns address of local variable [enabled by default] . This warning is referring to the line

This question already has an answer here: warning: implicit declaration of function 6 answers I wrote a simple program to find the Sum, average, biggest and smallest number of 3 numbers. It lets the user to input three (integer) numbers and return the sum, average, max and min. It has no errors but a warning. Here is my source code: main.c: #include <stdio.h> int main() { int num1, num2, num3, sum, max, min, avg; printf("Enter Three \"Integer\" Numbers:"); scanf("%i%i%i", &num1, &num2, &num3); sum = summation(&num1, &num2, &num3); avg = average(&sum); max = max_val(&num1, &num2, &num3); min =