math.h

when I try to compile this simple code from terminal: #include<stdio.h> int main(void) { printf("%f\n",sqrt(10)); return 0; } using gcc main.c command, it gets compiled and a.out gives correct answer. It means that that maths functions are added in C standard library which gets linked automatically. But if compile the same code in Eclipse IDE without adding any library to properties, it gives undefined reference error. It means maths functions are not part of C standard library. What is the truth? You may be seeing constant folding here, where using a constant in the math function call will

(This is my first question ever on StackOverflow) I have to use a Mac at work, and I'm coding in C++ with Code::Blocks (because I am used to this IDE). 2 days ago I upgraded from MacOS High Sierra to MacOS Mojave and I can fairly say that... it was a bad decision. Now, when trying to #include <math.h> I get this error : fatal error: sys/cdefs.h: No such file or directory . I have tried to reinstall the xcode line command tools with xcode-select --install , but it still doesn't work. Does anybody have a clue of what is going on, and how I could solve this issue ? The accepted answer doesn't

This question already has an answer here: cmath header confusion 4 answers I had a problem previously because of functions being overloaded without std:: . And the curse is still happening every now and then because I don't use using namespace std; . Removing using namespace std causes the program to get crap results Is there a way to disable all those non-std functions that come from c and only work with c++ functions under the namespace std (without having to use using namespace std; )? In other words: I want to get an error if I use sin() rather than std::sin() so that I won't do that

This compiles fine #include <math.h> int main(void) { double i = sqrt(9.0); } If I change 9.0 to -9.0, then my compiler (GNU C) gives an error about an undefined reference to 'sqrt'. I was expecting the sqrt function to return NaN or an exception. How does the C library only define sqrt for non-negative arguments? This is happening because gcc can use builtin functions during the optimization process to compute certain functions including sqrt at compile time in many but not all cases. If that is the case it will not need to emit a call to sqrt and therefore will not need to link against libm

I'm currently writing a C++ application which implements an Oscillator in conjuction with math.h. The code I have should work fine for the application (trying to compile an object file), bu I'm getting a compiler error most likely having to do with syntax/etc; I think it has something to do with namespace. The error: Terminal Output: User-Name-Macbook-Pro:Synth Parts UserName$ make g++ -o Oscillators.o -c -I. Oscillators.cpp -c In file included from Oscillators.cpp:2: /usr/include/math.h:41: error: expected unqualified-id before string constant In file included from /usr/include/c++/4.2.1/bits