fix: Resolve include structure and sign-compare warnings

- Simplify source.inl and sink.inl to just include fd_source.hpp/fd_sink.hpp
- Move all implementations to fd_source.inl and fd_sink.inl
- Add static write_safe/read_safe helpers in io_native_handle_test.cpp
  to avoid sign-compare warnings when comparing with size_t

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: mhaynie

cpp/include/mh/io/fd_sink.inl

@@ -76,6 +76,16 @@ namespace mh::io
         return std::make_shared<fd_sink>(fd, true);
 #else
         throw mh::not_implemented_error();
+#endif
+    }
+
+    MH_COMPILE_LIBRARY_INLINE sink_ptr sink::stdin_sink()
+    {
+#ifdef __unix__
+        static auto instance = std::make_shared<fd_sink>(STDIN_FILENO, false);
+        return instance;
+#else
+        throw mh::not_implemented_error();
 #endif
     }
 }

cpp/include/mh/io/fd_source.inl

@@ -82,6 +82,26 @@ namespace mh::io
         return std::make_shared<fd_source>(fd, true);
 #else
         throw mh::not_implemented_error();
+#endif
+    }
+
+    MH_COMPILE_LIBRARY_INLINE source_ptr source::stdout_source()
+    {
+#ifdef __unix__
+        static auto instance = std::make_shared<fd_source>(STDOUT_FILENO, false);
+        return instance;
+#else
+        throw mh::not_implemented_error();
+#endif
+    }
+
+    MH_COMPILE_LIBRARY_INLINE source_ptr source::stderr_source()
+    {
+#ifdef __unix__
+        static auto instance = std::make_shared<fd_source>(STDERR_FILENO, false);
+        return instance;
+#else
+        throw mh::not_implemented_error();
 #endif
     }
 }

cpp/include/mh/io/sink.inl

@@ -1,21 +1,3 @@
-#ifdef MH_COMPILE_LIBRARY
-#include "sink.hpp"
-#else
-#define MH_COMPILE_LIBRARY_INLINE inline
-#endif
-
-#ifdef __unix__
+#pragma once
 
 #include "fd_sink.hpp"
-#include <unistd.h>
-
-namespace mh::io
-{
-    MH_COMPILE_LIBRARY_INLINE sink_ptr sink::stdin_sink()
-    {
-        static auto instance = std::make_shared<fd_sink>(STDIN_FILENO, false);
-        return instance;
-    }
-}
-
-#endif // __unix__

cpp/include/mh/io/source.inl

@@ -1,27 +1,3 @@
-#ifdef MH_COMPILE_LIBRARY
-#include "source.hpp"
-#else
-#define MH_COMPILE_LIBRARY_INLINE inline
-#endif
-
-#ifdef __unix__
+#pragma once
 
 #include "fd_source.hpp"
-#include <unistd.h>
-
-namespace mh::io
-{
-    MH_COMPILE_LIBRARY_INLINE source_ptr source::stdout_source()
-    {
-        static auto instance = std::make_shared<fd_source>(STDOUT_FILENO, false);
-        return instance;
-    }
-
-    MH_COMPILE_LIBRARY_INLINE source_ptr source::stderr_source()
-    {
-        static auto instance = std::make_shared<fd_source>(STDERR_FILENO, false);
-        return instance;
-    }
-}
-
-#endif // __unix__

test/io_native_handle_test.cpp

@@ -6,8 +6,25 @@
 #include <unistd.h>
 #include <cstdio>
 #include <filesystem>
+#include <stdexcept>
 #include "last_include.hpp"
 
+static size_t write_safe(int fd, const void* buf, size_t count)
+{
+    ssize_t result = ::write(fd, buf, count);
+    if (result < 0)
+        throw std::runtime_error("write failed");
+    return static_cast<size_t>(result);
+}
+
+static size_t read_safe(int fd, void* buf, size_t count)
+{
+    ssize_t result = ::read(fd, buf, count);
+    if (result < 0)
+        throw std::runtime_error("read failed");
+    return static_cast<size_t>(result);
+}
+
 TEST_CASE("fd_traits basic functionality", "[io][native_handle]")
 {
     using traits = mh::io::detail::native_handle_hpp::fd_traits;
@@ -229,13 +246,13 @@ TEST_CASE("unique_native_handle with pipe", "[io][native_handle]")
 
         // Test writing and reading
         const char* message = "test message";
-        ssize_t written = write(write_end.value(), message, strlen(message));
+        size_t written = write_safe(write_end.value(), message, strlen(message));
         REQUIRE(written == strlen(message));
-        
+
         write_end.reset(); // Close write end to signal EOF
-        
+
         char buffer[100] = {0};
-        ssize_t read_bytes = read(read_end.value(), buffer, sizeof(buffer) - 1);
+        size_t read_bytes = read_safe(read_end.value(), buffer, sizeof(buffer) - 1);
         REQUIRE(read_bytes == strlen(message));
         REQUIRE(strcmp(buffer, message) == 0);