Cpp-Httplib usage with CMake

client.cpp

#include <iostream>
#include <cassert>
#include <functional>
#include <fstream>

#define CPPHTTPLIB_ZLIB_SUPPORT
#define CPPHTTPLIB_OPENSSL_SUPPORT
#include <httplib.h>

namespace h = httplib;

template<typename T> using shp = std::shared_ptr<T>;

int main(int argc, char** argv)
{
    std::cout << "\n [TRACE] Started Ok. " << "\n\n";

    // -------- E X P E R I M E N T / 1 --------------------------------------//
    //------------------------------------------------------------------------//
    std::cout << " [EXPERIMENT 1] HttpS (HTTP + SSL) Request " << '\n';
    std::puts(" ----------------------------------------------------");

    {
        h::SSLClient cli("www.httpbin.org");
        // cli.enable_server_certificate_verification(true);

        shp<h::Response> res = cli.Get("/get");
        assert( res != nullptr );

        if(res)
        {
            std::cout << "   => Http Version = " << res->version << '\n';
            std::cout << "   =>       Status = " << res->status << '\n';
            std::cout << "   => Content-Type = " << res->get_header_value("Content-Type") << '\n';

            std::puts(" --- All HTTP headers -----------");
            for( auto const& [key, value] : res->headers )
                std::cout << std::setw(40) << std::right << key
                          << "  "
                          << std::setw(35) << std::left  << value
                          << "\n";


            if(res->status == 200)
                std::cout << "\n [INFO] HTTP Response = " << res->body << '\n';

        }
    }

    // -------- E X P E R I M E N T / 1 --------------------------------------//
    //------------------------------------------------------------------------//
    std::cout << " [EXPERIMENT 2] Https (HTTP + SSL) ==>> Download binary file " << '\n';
    std::puts(" ----------------------------------------------------");

    auto ifs = std::ofstream("image.jpeg");

    auto cli = h::Client2("https://www.httpbin.org");
    auto res = cli.Get("/image/jpeg"
                       ,[&](const char* bytes, size_t len) -> bool
                        {
                            ifs.write(bytes, len);
                             // Note: return false for stopping processing the request
                            return true;
                        });

    // Status 200 means successful HTTP response from server.
    std::cout << " Res->status = " << res->status << '\n';

    std::cout << "\n [TRACE] Finish Ok. " << "\n";
    return 0;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.9)
project(httplib-client)

#========== Global Configurations =============#
#----------------------------------------------#

set(CMAKE_CXX_STANDARD 17)     
set(CMAKE_VERBOSE_MAKEFILE ON)
set(CMAKE_CXX_EXTENSIONS OFF)

# ------------ Download CPM CMake Script ----------------#

## Automatically donwload and use module CPM.cmake
file(DOWNLOAD https://raw.githubusercontent.com/TheLartians/CPM.cmake/v0.26.2/cmake/CPM.cmake
                 "${CMAKE_BINARY_DIR}/CPM.cmake")
include("${CMAKE_BINARY_DIR}/CPM.cmake")

#----------- Add dependencies --------------------------#

CPMAddPackage(
    NAME  httplib 
    URL  "https://github.com/yhirose/cpp-httplib/archive/v0.6.6.zip"
)

include_directories( ${httplib_SOURCE_DIR} )

find_package(PkgConfig REQUIRED)
pkg_search_module(OPENSSL REQUIRED openssl)

message([TRACE] " httplib source = ${httplib_SOURCE_DIR} ")
message([TRACE] " OPENSSL_LIBRARIES = ${OPENSSL_LIBRARIES} ")
    
#----------- Set targets -------------------------------#
add_executable(client client.cpp)

# Requires implementation of this for Windows.
IF(UNIX)
    target_link_libraries(client pthread z ${OPENSSL_LIBRARIES} )
ENDIF()