--- a/js/src/vm/ArrayBufferObject.h
+++ b/js/src/vm/ArrayBufferObject.h
@@ -502,32 +502,29 @@ ArrayBufferObjectMaybeShared& AsArrayBuf
 ArrayBufferObjectMaybeShared& AsArrayBufferMaybeShared(JSObject* obj);
 
 extern uint32_t JS_FASTCALL
 ClampDoubleToUint8(const double x);
 
 struct uint8_clamped {
     uint8_t val;
 
-    uint8_clamped() { }
-    uint8_clamped(const uint8_clamped& other) : val(other.val) { }
+    uint8_clamped() = default;
+    uint8_clamped(const uint8_clamped& other) = default;
 
     // invoke our assignment helpers for constructor conversion
     explicit uint8_clamped(uint8_t x)    { *this = x; }
     explicit uint8_clamped(uint16_t x)   { *this = x; }
     explicit uint8_clamped(uint32_t x)   { *this = x; }
     explicit uint8_clamped(int8_t x)     { *this = x; }
     explicit uint8_clamped(int16_t x)    { *this = x; }
     explicit uint8_clamped(int32_t x)    { *this = x; }
     explicit uint8_clamped(double x)     { *this = x; }
 
-    uint8_clamped& operator=(const uint8_clamped& x) {
-        val = x.val;
-        return *this;
-    }
+    uint8_clamped& operator=(const uint8_clamped& x) = default;
 
     uint8_clamped& operator=(uint8_t x) {
         val = x;
         return *this;
     }
 
     uint8_clamped& operator=(uint16_t x) {
         val = (x > 255) ? 255 : uint8_t(x);