1 files changed, 58 insertions, 0 deletions
diff --git a/deimos/core/format.h b/deimos/core/format.h
new file mode 100644
index 0000000..98d9001
--- /dev/null
+++ b/deimos/core/format.h
@@ -0,0 +1,58 @@
+#pragma once
+
+#include "deimos/core/base.h"
+
+namespace deimos
+{
+
+class IWriter;
+
+struct FormatArg
+{
+    enum Type : uint8_t
+    {
+        kInteger,
+        kUnsignedInteger,
+        kString,
+    };
+
+    Type type;
+
+    union
+    {
+        int64_t     integer;
+        uint64_t    unsigned_integer;
+
+        // @Todo Use string views
+        Span<const char> string;
+    };
+
+    explicit FormatArg(std::signed_integral auto value) :
+        type{kInteger},
+        integer{value}
+    {}
+
+    explicit FormatArg(std::unsigned_integral auto value) :
+        type{kUnsignedInteger},
+        unsigned_integer{value}
+    {}
+
+    explicit FormatArg(gsl::czstring value) :
+        type{kString},
+        string{value, (int64_t)__builtin_strlen(value)}
+    {}
+};
+
+template<typename T>
+concept Formattable = requires (T value) { FormatArg(value); };
+
+void FormatVa(IWriter*, gsl::czstring fmt, Span<const FormatArg>);
+
+template<Formattable... Args>
+void Format(IWriter* writer, gsl::czstring fmt, Args&&... args)
+{
+    FormatVa(writer, fmt, { FormatArg(std::forward<Args>(args))... });
+}
+
+} // namespace deimos
+