A packed [Array] of 64-bit integers. An [Array] specifically designed to hold 64-bit integer values. Packs data tightly, so it saves memory for large array sizes. [b]Note:[/b] This type stores signed 64-bit integers, which means it can take values in the interval [code][-2^63, 2^63 - 1][/code], i.e. [code][-9223372036854775808, 9223372036854775807][/code]. Exceeding those bounds will wrap around. If you only need to pack 32-bit integers tightly, see [PackedInt32Array] for a more memory-friendly alternative. Constructs an empty [PackedInt64Array]. Constructs a [PackedInt64Array] as a copy of the given [PackedInt64Array]. Constructs a new [PackedInt64Array]. Optionally, you can pass in a generic [Array] that will be converted. Appends an element at the end of the array (alias of [method push_back]). Appends a [PackedInt64Array] at the end of this array. Finds the index of an existing value (or the insertion index that maintains sorting order, if the value is not yet present in the array) using binary search. Optionally, a [code]before[/code] specifier can be passed. If [code]false[/code], the returned index comes after all existing entries of the value in the array. [b]Note:[/b] Calling [method bsearch] on an unsorted array results in unexpected behavior. Creates a copy of the array, and returns it. Assigns the given value to all elements in the array. This can typically be used together with [method resize] to create an array with a given size and initialized elements. Returns [code]true[/code] if the array contains [code]value[/code]. Inserts a new integer at a given position in the array. The position must be valid, or at the end of the array ([code]idx == size()[/code]). Returns [code]true[/code] if the array is empty. Appends a value to the array. Removes an element from the array by index. Sets the size of the array. If the array is grown, reserves elements at the end of the array. If the array is shrunk, truncates the array to the new size. Reverses the order of the elements in the array. Changes the integer at the given index. Returns the number of elements in the array. Sorts the elements of the array in ascending order. Returns a copy of the data converted to a [PackedByteArray], where each element have been encoded as 8 bytes. The size of the new array will be [code]int64_array.size() * 8[/code].