AP_Common: make Bitmask a template on number of bits

libraries/AP_Common/Bitmask.cpp

@@ -1,24 +0,0 @@
-#include "Bitmask.h"
-
-#include <AP_HAL/AP_HAL.h>
-
-Bitmask &Bitmask::operator=(const Bitmask&other)
-{
-    if (other.numwords != numwords || other.numbits != numbits) {
-#if CONFIG_HAL_BOARD == HAL_BOARD_SITL
-        // we really should not be assigning from a bitmask of a
-        // different number of bits!
-        AP_HAL::panic("attempt to copy from bitmask of different size");
-#endif
-        // ... but try to cope if it happens in real life:
-        if (numwords != other.numwords) {
-            delete bits;
-            bits = new uint32_t[numwords];
-            numwords = other.numwords;
-        }
-        numbits = other.numbits;
-    }
-    memcpy(bits, other.bits, sizeof(bits[0])*other.numwords);
-
-    return *this;
-}

libraries/AP_Common/Bitmask.h

@@ -21,19 +21,20 @@
 #include <stdint.h>
 #include <string.h>
 
+template<uint16_t num_bits>
 class Bitmask {
 public:
-    Bitmask(uint16_t num_bits) :
+    Bitmask() :
         numbits(num_bits),
         numwords((num_bits+31)/32) {
-        bits = new uint32_t[numwords];
         clearall();
     }
-    ~Bitmask(void) {
-        delete[] bits;
+
+    Bitmask &operator=(const Bitmask&other) {
+        memcpy(bits, other.bits, sizeof(bits[0])*other.numwords);
+        return *this;
     }
 
-    Bitmask &operator=(const Bitmask&other);
     Bitmask(const Bitmask &other) = delete;
 
     // set given bitnumber
@@ -129,5 +130,5 @@ public:
 private:
     uint16_t numbits;
     uint16_t numwords;
-    uint32_t *bits;
+    uint32_t bits[(num_bits+31)/32];
 };

libraries/AP_Common/tests/test_bitmask.cpp

@@ -4,7 +4,7 @@
 
 TEST(Bitmask, Tests)
 {
-    Bitmask x{49};
+    Bitmask<49> x;
 
     EXPECT_EQ(-1, x.first_set());
     x.set(5);
@@ -40,7 +40,7 @@ TEST(Bitmask, Tests)
 
 TEST(Bitmask, SetAll)
 {
-    Bitmask x{49};
+    Bitmask<49> x;
     EXPECT_EQ(-1, x.first_set());
     EXPECT_EQ(false, x.get(45));
     x.setall();
@@ -59,13 +59,13 @@ TEST(Bitmask, SetAll)
 
 TEST(Bitmask, Assignment)
 {
-    Bitmask x{49};
+    Bitmask<49> x;
     x.set(0);
     x.set(5);
     x.set(6);
     x.set(48);
 
-    Bitmask y{49};
+    Bitmask<49> y;
     y = x;
     x.clear(0);
     EXPECT_EQ(true, y.get(0));