asio with cpm

examples/asio_http_client.cpp

@@ -9,8 +9,6 @@
 //
 
 #include <iostream>
-#include <istream>
-#include <ostream>
 #include <string>
 #include "asio/ts/internet.hpp"
 

examples/asio_tcp_clients.cpp

@@ -1,32 +1,30 @@
 #include <iostream>
+
 #include "asio.hpp"
 
+int main(int argc, char** argv) {
 
-int main(int argc, char ** argv) {
+  using namespace asio;
+  io_context ctx;
+  ip::tcp::resolver resolver(ctx);
+  ip::tcp::resolver::results_type results = resolver.resolve("www.boost.org", "https");
 
-    using namespace asio;
-    io_context ctx;
-    ip::tcp::resolver resolver(ctx);
-    ip::tcp::resolver::query query("www.boost.org", "https");
+  // End points
+  for (const auto& endpoint : results) {
+    std::cout << endpoint.endpoint() << std::endl;
+  }
 
-    // End points    
-    {
-        ip::tcp::resolver::iterator iter = resolver.resolve(query);
-        ip::tcp::resolver::iterator end; // End marker.
-
-        while (iter != end) {
-            ip::tcp::endpoint endpoint = *iter++;
-            std::cout << endpoint << std::endl;
-        }
+  ip::tcp::socket sokt(ctx);
+  async_connect(sokt, results, [](const error_code& er, const ip::tcp::endpoint& endpoint) {
+    if (!er) {
+      std::cout << "Connected to: " << endpoint << std::endl;
+    } else {
+      std::cout << "async_connect error: " << er.message() << std::endl;
     }
+  });
 
-    ip::tcp::socket sokt(ctx);
-    async_connect(sokt, resolver.resolve(query), [](const error_code& er, const ip::tcp::endpoint& endpoint) {
-        if (!er) {
+  // Run the io_context to handle the asynchronous operations
+  ctx.run();
 
-        } else {
-            std::cout << "async_connect error:" << er.message() << std::endl;
-        }
-    });
-    return 0;
-}
+  return 0;
+}

third_party/asio/CMakeLists.txt

@@ -1,13 +1,45 @@
-add_library(asio INTERFACE)
-target_include_directories(asio
-  INTERFACE
-    "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>"
-)
-
-if (WIN32)
-  target_compile_definitions(asio INTERFACE -DASIO_HAS_STD_THREAD -DASIO_STANDALONE -D_WIN32_WINNT=0x0600)
-else(WIN32)
-  target_compile_definitions(asio INTERFACE -DASIO_HAS_STD_THREAD -DASIO_STANDALONE)
-  target_compile_options(asio INTERFACE -Wno-shadow -Wno-implicit-fallthrough)
-endif()
+find_package(Threads REQUIRED)
+CPMAddPackage("gh:chriskohlhoff/asio#[email protected]")
+
+# ASIO doesn't use CMake, we have to configure it manually. Extra notes for using on Windows:
+#
+# 1) If _WIN32_WINNT is not set, ASIO assumes _WIN32_WINNT=0x0501, i.e. Windows XP target, which is
+# definitely not the platform which most users target.
+#
+# 2) WIN32_LEAN_AND_MEAN is defined to make Winsock2 work.
+if(asio_ADDED)
+  add_library(asio INTERFACE)
+  target_include_directories(asio SYSTEM INTERFACE ${asio_SOURCE_DIR}/asio/include)
+  target_compile_definitions(asio INTERFACE ASIO_STANDALONE ASIO_NO_DEPRECATED)
+  target_link_libraries(asio INTERFACE Threads::Threads)
+
+  if(WIN32)
+    # macro see @ https://stackoverflow.com/a/40217291/1746503
+    macro(get_win32_winnt version)
+      if(CMAKE_SYSTEM_VERSION)
+        set(ver ${CMAKE_SYSTEM_VERSION})
+        string(REGEX MATCH "^([0-9]+).([0-9])" ver ${ver})
+        string(REGEX MATCH "^([0-9]+)" verMajor ${ver})
+        # Check for Windows 10, b/c we'll need to convert to hex 'A'.
+        if("${verMajor}" MATCHES "10")
+          set(verMajor "A")
+          string(REGEX REPLACE "^([0-9]+)" ${verMajor} ver ${ver})
+        endif("${verMajor}" MATCHES "10")
+        # Remove all remaining '.' characters.
+        string(REPLACE "." "" ver ${ver})
+        # Prepend each digit with a zero.
+        string(REGEX REPLACE "([0-9A-Z])" "0\\1" ver ${ver})
+        set(${version} "0x${ver}")
+      endif()
+    endmacro()
 
+    if(NOT DEFINED _WIN32_WINNT)
+      get_win32_winnt(ver)
+      set(_WIN32_WINNT ${ver})
+    endif()
+
+    message(STATUS "Set _WIN32_WINNET=${_WIN32_WINNT}")
+
+    target_compile_definitions(asio INTERFACE _WIN32_WINNT=${_WIN32_WINNT} WIN32_LEAN_AND_MEAN)
+  endif()
+endif()