4 files changed, 13 insertions, 4 deletions
diff --git a/deimos/core/base.h b/deimos/core/base.h
index 3dc3bad..c3b0d87 100644
--- a/deimos/core/base.h
+++ b/deimos/core/base.h
@@ -65,6 +65,13 @@ public:
 
     deimos_DEFAULT_COPY_MOVE(Span);
 
+    constexpr Span(T* begin, int64_t size) :
+        m_begin{begin},
+        m_size{size}
+    {
+        Expects(size >= 0);
+    }
+
     template<typename U>
     requires std::convertible_to<U*, T*>
     constexpr Span(const Span<U>& other) : // NOLINT
@@ -72,6 +79,7 @@ public:
         m_size{other.size()}
     {}
 
+    constexpr T* data() const { return m_begin; }
     constexpr T* begin() const { return m_begin; }
     constexpr T* end() const { return m_begin + m_size; }
     constexpr int64_t size() const { return m_size; }
diff --git a/deimos/core/gsl.h b/deimos/core/gsl.h
index b6a9804..2000f6a 100644
--- a/deimos/core/gsl.h
+++ b/deimos/core/gsl.h
@@ -8,3 +8,5 @@ using czstring  = const char*;
 
 } // namespace gsl
 
+#define Expects(EXPR) do { if (!(EXPR)) { __builtin_trap(); } } while (0)
+#define Ensures(EXPR) do { if (!(EXPR)) { __builtin_trap(); } } while (0)
diff --git a/deimos/core/os.h b/deimos/core/os.h
index af01853..95b662b 100644
--- a/deimos/core/os.h
+++ b/deimos/core/os.h
@@ -21,8 +21,7 @@ public:
 
     virtual ~OsConsoleApi() = default;
 
-    // @Todo Use span
-    virtual void Write(OsConsoleType, const char* data, int64_t length) = 0;
+    virtual void Write(OsConsoleType, Span<const char> data) = 0;
 };
 
 class OsApi
diff --git a/deimos/core/os_win32.cpp b/deimos/core/os_win32.cpp
index 3f724ef..fbc75c4 100644
--- a/deimos/core/os_win32.cpp
+++ b/deimos/core/os_win32.cpp
@@ -29,9 +29,9 @@ public:
         m_stderr{::GetStdHandle(STD_ERROR_HANDLE)}
     {}
 
-    void Write(OsConsoleType type, const char* data, int64_t length) override
+    void Write(OsConsoleType type, Span<const char> data) override
     {
-        ::WriteConsoleA(Handle(type), data, (DWORD)length, nullptr, nullptr);
+        ::WriteConsoleA(Handle(type), data.data(), (DWORD)data.size(), nullptr, nullptr);
     }
 };