/in/foo.cc:2:1: error: stray '##' in program
 ##pragmapr  GCC optimize("O3")
 ^~
/in/foo.cc:6:1: error: stray '##' in program
 ##pragmapr  GCC optimize("O3")
 ^~
/in/foo.cc:10:1: error: stray '##' in program
 ##pragmapr  GCC optimize("O3")
 ^~
/in/foo.cc:2:3: error: 'pragmapr' does not name a type
 ##pragmapr  GCC optimize("O3")
   ^~~~~~~~
/in/foo.cc:3:27: error: expected declaration before end of line
 #pragma GCC optimize("O3")
                           ^