A Bitmap class, basically a wrapper for bit shifting and masking

src/kstd/Bitmap.hh

@@ -0,0 +1,100 @@
+/* Bitmap.hh
+ * vim: set tw=80:
+ * Eryn Wells <eryn@erynwells.me>
+ */
+/**
+ * Declares a Bitmap object, which manages an array of bytes.
+ */
+
+#ifndef __KSTD_BITMAP_HH__
+#define __KSTD_BITMAP_HH__
+
+#include "kstd/Types.hh"
+
+namespace kstd {
+
+/** An array-like object of N bits, where N is the size of the type T given as a template parameter. */
+template <typename T>
+struct Bitmap
+{
+    typedef T FieldType;
+
+    /** Size of the bitmap in bits. */
+    static const usize length = sizeof(FieldType) * 8;
+
+    Bitmap()
+        : mBitmap(0)
+    { }
+
+    explicit
+    Bitmap(FieldType value)
+        : mBitmap(value)
+    { }
+
+    /** Get the status of a single bit. Returns `true` if the bit is 1. */
+    bool
+    isSet(usize bit)
+        const
+    {
+        if (isValid(bit)) {
+            return (mBitmap & (1 << bit)) > 0;
+        }
+        return false;
+    }
+
+    /** Set a single bit to 1. */
+    void
+    set(usize bit)
+    {
+        if (isValid(bit)) {
+            mBitmap |= 1 << bit;
+        }
+    }
+
+    /** Set a single bit to zero. */
+    void
+    clear(usize bit)
+    {
+        if (isValid(bit)) {
+            mBitmap &= ~(1 << bit);
+        }
+    }
+
+    /** Toggle the state of a single bit. Returns `true` if the bit was set to 1. */
+    bool
+    toggle(usize bit)
+    {
+        if (isValid(bit)) {
+            mBitmap ^= 1 << bit;
+            return isSet(bit);
+        }
+        return false;
+    }
+
+    /** Clear the entire bit field. */
+    void
+    zero()
+    {
+        mBitmap = 0;
+    }
+
+    /** Set everything to 1. */
+    void
+    fill()
+    {
+        mBitmap = ~(0);
+    }
+
+private:
+    FieldType mBitmap;
+
+    inline bool
+    isValid(usize bit)
+    {
+        return bit >= 0 && bit < Bitmap::length;
+    }
+};
+
+} /* namespace kstd */
+
+#endif /* __KSTD_BITMAP_HH__ */