Fix C++17 build, use int64 ID and fix Linux build

CMakeLists.txt

@@ -194,7 +194,10 @@ if(MCP_USE_LLHTTP)
 
         add_library(llhttp STATIC ${LLHTTP_SOURCES})
         target_include_directories(llhttp PUBLIC ${llhttp_SOURCE_DIR}/include)
-
+
+        # Enable position-independent code for shared library linking
+        set_target_properties(llhttp PROPERTIES POSITION_INDEPENDENT_CODE ON)
+
         # Disable warnings for third-party code
         if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
             target_compile_options(llhttp PRIVATE -w)
@@ -245,7 +248,12 @@ if(MCP_USE_NGHTTP2)
         message(STATUS "nghttp2 is a larger dependency and requires compilation. Please be patient.")
         FetchContent_MakeAvailable(nghttp2)
         message(STATUS "nghttp2 download and configuration complete.")
-
+
+        # Enable position-independent code for shared library linking
+        if(TARGET nghttp2_static)
+            set_target_properties(nghttp2_static PROPERTIES POSITION_INDEPENDENT_CODE ON)
+        endif()
+
         set(NGHTTP2_FOUND TRUE)
         set(NGHTTP2_INCLUDE_DIRS 
             ${nghttp2_SOURCE_DIR}/lib/includes 

Makefile

@@ -107,6 +107,16 @@ verbose:
 	@./build.sh --verbose
 
 # Format all source files (C++ and TypeScript)
+format-cpp:
+	@echo "Formatting C++ files with clang-format..."
+	@if command -v clang-format >/dev/null 2>&1; then \
+	        find . -path "./build*" -prune -o \( -name "*.h" -o -name "*.cpp" -o -name "*.cc" \) -print | xargs clang-format -i; \
+	        echo "C++ formatting complete."; \
+	else \
+	        echo "Warning: clang-format not found, skipping C++ formatting."; \
+	        echo "Install clang-format to format C++ files: brew install clang-format (macOS) or apt-get install clang-format (Ubuntu)"; \
+	fi
+
 format:
 	@echo "Formatting all source files..."
 	@echo "Formatting C++ files with clang-format..."
@@ -709,6 +719,7 @@ help:
 	@echo ""
 	@echo "┌─ CODE QUALITY TARGETS ──────────────────────────────────────────────┐"
 	@echo "│ make format        Auto-format all source files (C++, TypeScript, Python, Rust, Ruby, C#, Go, Java) │"
+	@echo "│ make format-cpp    Format only C++ files with clang-format           │"
 	@echo "│ make format-ts     Format only TypeScript files with prettier        │"
 	@echo "│ make format-python Format only Python files with black               │"
 	@echo "│ make format-rust   Format only Rust files with rustfmt               │"
@@ -734,6 +745,7 @@ help:
 	@echo "│                                                                       │"
 	@echo "│ Development workflow:                                                │"
 	@echo "│   $$ make format          # Format all code (C++, TypeScript, Python, Rust, Ruby, C#, Go, Java) │"
+	@echo "│   $$ make format-cpp      # Format only C++ files                    │"
 	@echo "│   $$ make format-ts       # Format only TypeScript files             │"
 	@echo "│   $$ make format-python   # Format only Python files                 │"
 	@echo "│   $$ make format-rust     # Format only Rust files                   │"

build.sh

@@ -134,9 +134,9 @@ fi
 # Run tests if requested
 if [ "$RUN_TESTS" = true ]; then
     print_status "Running tests..."
-    
+
     # Run all tests using ctest
-    if GTEST_COLOR=1 ctest --output-on-failure --verbose -C $BUILD_TYPE; then
+    if GTEST_COLOR=1 ctest --output-on-failure -C $BUILD_TYPE; then
         print_success "All tests passed!"
     else
         print_error "Some tests failed"

examples/event_loop_example.cc

@@ -1,5 +1,6 @@
 #include <atomic>
 #include <chrono>
+#include <csignal>
 #include <fcntl.h>
 #include <iostream>
 #include <thread>

examples/mcp/mcp_example_server.cc

@@ -251,13 +251,13 @@ CallToolResult executeSampleTool(const std::string& name,
                          : "";
     double a = holds_alternative<double>(a_it->second)
                    ? get<double>(a_it->second)
-                   : (holds_alternative<long long>(a_it->second)
-                          ? static_cast<double>(get<long long>(a_it->second))
+                   : (holds_alternative<int64_t>(a_it->second)
+                          ? static_cast<double>(get<int64_t>(a_it->second))
                           : 0.0);
     double b = holds_alternative<double>(b_it->second)
                    ? get<double>(b_it->second)
-                   : (holds_alternative<long long>(b_it->second)
-                          ? static_cast<double>(get<long long>(b_it->second))
+                   : (holds_alternative<int64_t>(b_it->second)
+                          ? static_cast<double>(get<int64_t>(b_it->second))
                           : 0.0);
 
     double calc_result = 0;

include/mcp/c_api/mcp_c_bridge.h

@@ -648,20 +648,20 @@ inline mcp_request_id_t to_c_request_id_safe(const mcp::RequestId& id) {
     const auto& str = mcp::get<std::string>(id);
     return mcp_request_id_create_string(str.c_str());
   } else {
-    return mcp_request_id_create_number(mcp::get<int>(id));
+    return mcp_request_id_create_number(mcp::get<int64_t>(id));
   }
 }
 
 inline mcp::RequestId to_cpp_request_id_safe(mcp_request_id_t id) {
   if (!id) {
-    return mcp::RequestId(0);
+    return mcp::RequestId(static_cast<int64_t>(0));
   }
 
   if (mcp_request_id_is_string(id)) {
     const char* str = mcp_request_id_get_string(id);
     return mcp::RequestId(str ? std::string(str) : std::string());
   } else {
-    return mcp::RequestId(static_cast<int>(mcp_request_id_get_number(id)));
+    return mcp::RequestId(static_cast<int64_t>(mcp_request_id_get_number(id)));
   }
 }
 

include/mcp/c_api/mcp_c_type_conversions.h

@@ -291,7 +291,7 @@ inline RequestId to_cpp_request_id(const mcp_request_id_t& id) {
   if (id.type == mcp_request_id::MCP_REQUEST_ID_STRING) {
     return RequestId(to_cpp_string(id.value.string_value));
   } else {
-    return RequestId(static_cast<int>(id.value.number_value));
+    return RequestId(static_cast<int64_t>(id.value.number_value));
   }
 }
 
@@ -305,7 +305,7 @@ inline mcp_request_id_t to_c_request_id(const RequestId& id) {
     result.value.string_value = to_c_string(mcp::get<std::string>(id));
   } else {
     result.type = mcp_request_id::MCP_REQUEST_ID_NUMBER;
-    result.value.number_value = mcp::get<int>(id);
+    result.value.number_value = mcp::get<int64_t>(id);
   }
   return result;
 }
@@ -322,7 +322,7 @@ inline ProgressToken to_cpp_progress_token(const mcp_progress_token_t& token) {
   if (token.type == mcp_progress_token::MCP_PROGRESS_TOKEN_STRING) {
     return ProgressToken(to_cpp_string(token.value.string_value));
   } else {
-    return ProgressToken(static_cast<int>(token.value.number_value));
+    return ProgressToken(static_cast<int64_t>(token.value.number_value));
   }
 }
 
@@ -336,7 +336,7 @@ inline mcp_progress_token_t to_c_progress_token(const ProgressToken& token) {
     result.value.string_value = to_c_string(mcp::get<std::string>(token));
   } else {
     result.type = mcp_progress_token::MCP_PROGRESS_TOKEN_NUMBER;
-    result.value.number_value = mcp::get<int>(token);
+    result.value.number_value = mcp::get<int64_t>(token);
   }
   return result;
 }

include/mcp/c_api/mcp_c_types.h

@@ -39,7 +39,7 @@ extern "C" {
 #define MCP_API_EXPORT __attribute__((visibility("default")))
 #define MCP_API_IMPORT
 #define MCP_CALLBACK
-#define MCP_NOEXCEPT __attribute__((nothrow))
+#define MCP_NOEXCEPT  // GCC 7 doesn't allow attributes on function definitions
 #else
 #define MCP_API_EXPORT
 #define MCP_API_IMPORT

include/mcp/client/mcp_client.h

@@ -293,15 +293,16 @@ class RequestTracker {
   // Add request to tracking
   void trackRequest(RequestPtr request) {
     std::lock_guard<std::mutex> lock(mutex_);
-    // Extract int ID from RequestId
-    int id = holds_alternative<int>(request->id) ? get<int>(request->id) : 0;
+    // Extract int64_t ID from RequestId
+    int64_t id =
+        holds_alternative<int64_t>(request->id) ? get<int64_t>(request->id) : 0;
     pending_requests_[id] = request;
   }
 
   // Get request by ID without removing
   RequestPtr getRequest(const RequestId& id) {
     std::lock_guard<std::mutex> lock(mutex_);
-    int int_id = holds_alternative<int>(id) ? get<int>(id) : 0;
+    int64_t int_id = holds_alternative<int64_t>(id) ? get<int64_t>(id) : 0;
     auto it = pending_requests_.find(int_id);
     if (it != pending_requests_.end()) {
       return it->second;
@@ -312,7 +313,7 @@ class RequestTracker {
   // Remove and return request
   RequestPtr removeRequest(const RequestId& id) {
     std::lock_guard<std::mutex> lock(mutex_);
-    int int_id = holds_alternative<int>(id) ? get<int>(id) : 0;
+    int64_t int_id = holds_alternative<int64_t>(id) ? get<int64_t>(id) : 0;
     auto it = pending_requests_.find(int_id);
     if (it != pending_requests_.end()) {
       auto request = it->second;
@@ -336,7 +337,9 @@ class RequestTracker {
 
     // Remove timed out requests from tracking
     for (const auto& request : timed_out) {
-      int id = holds_alternative<int>(request->id) ? get<int>(request->id) : 0;
+      int64_t id = holds_alternative<int64_t>(request->id)
+                       ? get<int64_t>(request->id)
+                       : 0;
       pending_requests_.erase(id);
     }
 
@@ -352,7 +355,7 @@ class RequestTracker {
   mutable std::mutex mutex_;
   std::chrono::milliseconds timeout_;
   // Store using int ID extracted from RequestId
-  std::unordered_map<int, RequestPtr> pending_requests_;
+  std::unordered_map<int64_t, RequestPtr> pending_requests_;
 };
 
 /**

include/mcp/core/compat.h

@@ -48,22 +48,8 @@ inline constexpr auto in_place = std::in_place;
 
 using bad_optional_access = std::bad_optional_access;
 
-// make_optional helpers
-template <typename T>
-constexpr optional<typename std::decay<T>::type> make_optional(T&& value) {
-  return std::make_optional(std::forward<T>(value));
-}
-
-template <typename T, typename... Args>
-constexpr optional<T> make_optional(Args&&... args) {
-  return std::make_optional<T>(std::forward<Args>(args)...);
-}
-
-template <typename T, typename U, typename... Args>
-constexpr optional<T> make_optional(std::initializer_list<U> il,
-                                    Args&&... args) {
-  return std::make_optional<T>(il, std::forward<Args>(args)...);
-}
+// Import std functions into mcp namespace
+using std::make_optional;
 #else
 // Use mcp:: implementations (already defined in optional.h)
 // Just need to ensure they're in the mcp namespace
@@ -75,77 +61,11 @@ using variant = std::variant<Types...>;
 
 using bad_variant_access = std::bad_variant_access;
 
-template <typename T, typename... Types>
-constexpr T* get_if(variant<Types...>* v) noexcept {
-  return std::get_if<T>(v);
-}
-
-template <typename T, typename... Types>
-constexpr const T* get_if(const variant<Types...>* v) noexcept {
-  return std::get_if<T>(v);
-}
-
-template <typename T, typename... Types>
-constexpr T& get(variant<Types...>& v) {
-  return std::get<T>(v);
-}
-
-template <typename T, typename... Types>
-constexpr const T& get(const variant<Types...>& v) {
-  return std::get<T>(v);
-}
-
-template <typename T, typename... Types>
-constexpr T&& get(variant<Types...>&& v) {
-  return std::get<T>(std::move(v));
-}
-
-template <typename T, typename... Types>
-constexpr const T&& get(const variant<Types...>&& v) {
-  return std::get<T>(std::move(v));
-}
-
-template <typename T, typename... Types>
-constexpr bool holds_alternative(const variant<Types...>& v) noexcept {
-  return std::holds_alternative<T>(v);
-}
-
-template <typename Visitor, typename... Variants>
-constexpr decltype(auto) visit(Visitor&& vis, Variants&&... vars) {
-  return std::visit(std::forward<Visitor>(vis),
-                    std::forward<Variants>(vars)...);
-}
-
-// Helper for index-based operations
-template <std::size_t I, typename... Types>
-constexpr auto& get(variant<Types...>& v) {
-  return std::get<I>(v);
-}
-
-template <std::size_t I, typename... Types>
-constexpr const auto& get(const variant<Types...>& v) {
-  return std::get<I>(v);
-}
-
-template <std::size_t I, typename... Types>
-constexpr auto&& get(variant<Types...>&& v) {
-  return std::get<I>(std::move(v));
-}
-
-template <std::size_t I, typename... Types>
-constexpr const auto&& get(const variant<Types...>&& v) {
-  return std::get<I>(std::move(v));
-}
-
-template <std::size_t I, typename... Types>
-constexpr auto* get_if(variant<Types...>* v) noexcept {
-  return std::get_if<I>(v);
-}
-
-template <std::size_t I, typename... Types>
-constexpr const auto* get_if(const variant<Types...>* v) noexcept {
-  return std::get_if<I>(v);
-}
+// Import std functions into mcp namespace for ADL
+using std::get;
+using std::get_if;
+using std::holds_alternative;
+using std::visit;
 #else
 // Use mcp:: implementations and provide std-like free functions
 

include/mcp/core/type_helpers.h

@@ -234,16 +234,26 @@ template <size_t N>
 struct string_literal {
   char value[N];
 
+#if __cplusplus >= 201703L
+  // C++17 and later: can use constexpr with loops
   constexpr string_literal(const char (&str)[N]) {
     for (size_t i = 0; i < N; ++i) {
       value[i] = str[i];
     }
   }
+#else
+  // C++14: constexpr constructors can't have loops
+  string_literal(const char (&str)[N]) {
+    for (size_t i = 0; i < N; ++i) {
+      value[i] = str[i];
+    }
+  }
+#endif
 
   constexpr const char* c_str() const { return value; }
   constexpr size_t size() const { return N - 1; }
 
-  constexpr bool operator==(const string_literal& other) const {
+  bool operator==(const string_literal& other) const {
     for (size_t i = 0; i < N; ++i) {
       if (value[i] != other.value[i])
         return false;
@@ -254,7 +264,7 @@ struct string_literal {
 
 // Deduction guide for C++17, but we'll use make function for C++14
 template <size_t N>
-constexpr string_literal<N> make_string_literal(const char (&str)[N]) {
+inline string_literal<N> make_string_literal(const char (&str)[N]) {
   return string_literal<N>(str);
 }
 
@@ -277,6 +287,11 @@ struct overload : Fs... {
 template <typename... Fs>
 overload(Fs...) -> overload<Fs...>;
 
+template <typename... Fs>
+constexpr auto make_overload(Fs&&... fs) {
+  return overload<Fs...>{std::forward<Fs>(fs)...};
+}
+
 template <typename Variant, typename... Visitors>
 auto match(Variant&& v, Visitors&&... visitors) {
   return std::visit(overload{std::forward<Visitors>(visitors)...},

include/mcp/echo/echo_basic.h

@@ -651,8 +651,8 @@ class EchoClientBase {
     std::lock_guard<std::mutex> lock(pending_mutex_);
 
     int id = 0;
-    if (holds_alternative<int>(response.id)) {
-      id = get<int>(response.id);
+    if (holds_alternative<int64_t>(response.id)) {
+      id = get<int64_t>(response.id);
     }
 
     auto it = pending_requests_.find(id);

include/mcp/filter/metrics_filter.h

@@ -232,7 +232,7 @@ class MetricsFilter : public network::NetworkFilterBase,
     }
 
     // Start tracking request latency
-    if (holds_alternative<int>(request.id) ||
+    if (holds_alternative<int64_t>(request.id) ||
         holds_alternative<std::string>(request.id)) {
       std::lock_guard<std::mutex> lock(request_mutex_);
       pending_requests_[requestIdToString(request.id)] =

include/mcp/io_result.h

@@ -3,6 +3,7 @@
 
 #include <cerrno>
 #include <cstring>
+#include <string>
 
 #ifdef _WIN32
 #include <winsock2.h>