Update ex1_16.cpp
Update ex1_16.cpp
Soyn/Cpp-Primer,coldmanck/Cpp-Primer,sanerror/Cpp-Primer,andersy005/Cpp-Primer,XDXX/Cpp-Primer,AndychenCL/Cpp-Primer,andersy005/Cpp-Primer,Mooophy/Cpp-Primer,XDXX/Cpp-Primer,Squawk09/Cpp-Primer,Squawk09/Cpp-Primer,Mooophy/Cpp-Primer,sanerror/Cpp-Primer,coldmanck/Cpp-Primer,Soyn/Cpp-Primer,AndychenCL/Cpp-Primer