Install libgflags-dev by entering the following commands in the terminal:
sudo apt update sudo apt install libgflags-dev
Description:
commandline flags module for C++ (development files)
gflags is a library that implements commandline flags processing. As such it's a replacement for getopt(). It has increased flexibility, including built-in support for C++ types like string, and the ability to define flags in the source file in which they're used. . This package contains development libraries and header files.
Homepage: http://gflags.github.io/gflags/
Version: 2.2.1-1
Section: universe/libdevel