Out of the box, Haiku nightly’s llvm_clang package appears to be unaware of the locations of the standard C/C++ headers, such as iostream and bits/c++config.h, causing clang++ builds to fail.
Example:
#include <iostream>
using std::cout;
int main() {
cout << "Hello World!\n";
return 0;
}
Trace:
$ clang++ -o hello hello.cpp
hello.cpp:1:10: fatal error: 'iostream' file not found
#include <iostream>
^~~~~~~~~~
1 error generated.
As a workaround, I am manually adding the include paths:
$ clang++ -o hello -I /boot/system/develop/tools/lib/gcc/x86_64-unknown-haiku/5.4.0/include/c++ -I /boot/system/develop/tools/lib/gcc/x86_64-unknown-haiku/5.4.0/include/c++/x86_64-unknown-haiku hello.cpp
$ ./hello
Hello World!
Update
In Haiku nightly x86, the llvm_x86_clang package fails to inform its clang++ binary of yet another location, for things like float.h in /boot/system/lib/x86/clang/5.0.0/include. 