Can't compile a Crow sample - boost/optional.hpp: No such file or directory

Question

I'd like to compile and test Crow C++ microframework in Debian Linux 11:

1. Download the latest crow.deb, currently crow-v1.0+1.deb.

2. Install it:

   $ sudo dpkg -i crow-v1.0+1.deb
   Selecting previously unselected package crow.
   (Reading database ... 587955 files and directories currently installed.)
   Preparing to unpack crow-v1.0+1.deb ...
   Unpacking crow (1.0+1) ...
   Setting up crow (1.0+1) ...
   

3. Create a .cpp file with a sample code from crowcpp.org:

   $ echo '#include "crow.h"
   
   int main()
   {
       crow::SimpleApp app;
   
       CROW_ROUTE(app, "/")([](){
           return "Hello world";
       });
   
       app.port(18080).run();
   }' > crowtest.cpp
   

4. Try to compile it:

   $ g++ crowtest.cpp -lpthread
    In file included from /usr/include/crow.h:2,
                     from crowtest.cpp:1:
    /usr/include/crow/query_string.h:9:10: fatal error: boost/optional.hpp: No such file or directory
        9 | #include <boost/optional.hpp>
          |          ^~~~~~~~~~~~~~~~~~~~
    compilation terminated.
   

5. See the error above. How can I compile the Crow sample code?

Answer 1

You need to install Boost, for Debian that would be apt install libboost-dev.