{{keywords>freebsd,unix,uint,clang,gcc,cc,stdint,compile,compiling,c,unidentified,identifier}} ====== Use of undeclared identifier 'uint' when compiling in clang / gcc ====== ===== Environment ===== * FreeBSD * clang / gcc ===== Symptom ===== When attempting to compile a C program, in either ''clang'' or ''gcc'', you encounter an error similar to this one: myprogram.c:600:2: error: use of undeclared identifier 'uint'; did you mean 'int'? uint n=0; ^~~~ int ===== Root Cause ===== ''uint'' is not a [[https://en.wikipedia.org/wiki/C_data_types|standard C data type]], so it must be declared. ===== Solution ===== Include the ''sys/types.h'' header file before ''main'' in the C source file: #include The program should then compile.