<iostream> not usable

[Silver-Fang]

The inclusion of some standard library headers can cause compilation errors. For example:

#include <iostream>
void setup() {
}
void loop() {
}

C:\Users\vhtmf\AppData\Local\Temp\arduino\sketches\4F283322D1DC7D231547A617FD5B3E64\sketch\sketch_feb10a.ino.cpp.o: In function `__static_initialization_and_destruction_0':
c:\users\vhtmf\appdata\local\arduino15\packages\arduino\tools\arm-none-eabi-gcc\4.8.3-2014q1\arm-none-eabi\include\c++\4.8.3/iostream:74: undefined reference to `std::ios_base::Init::Init()'
c:\users\vhtmf\appdata\local\arduino15\packages\arduino\tools\arm-none-eabi-gcc\4.8.3-2014q1\arm-none-eabi\include\c++\4.8.3/iostream:74: undefined reference to `std::ios_base::Init::~Init()'
collect2.exe: error: ld returned 1 exit status

exit status 1

Compilation error: exit status 1

It seems that there are some functions declared in the header file that are not defined.

The standard library does not appear to be in this repository. Does anyone know where it's downloaded from? I installed the standard library automatically after installing the Arduino SAM Boards in the Arduino IDE Board Manager.