update demo to suppress warnings from g++
update demo to suppress warnings from g++

FFIG/ffig,jbcoe/C_API_generation,FFIG/ffig,FFIG/ffig,FFIG/ffig,jbcoe/C_API_generation,FFIG/ffig,jbcoe/C_API_generation,FFIG/ffig,jbcoe/C_API_generation,FFIG/ffig,FFIG/ffig