Function readInt [src]

Reads an integer from memory with bit count specified by T. The bit count of T must be evenly divisible by 8. This function cannot fail and cannot cause undefined behavior.

Prototype

pub inline fn readInt(comptime T: type, buffer: *const [@divExact(@typeInfo(T).int.bits, 8)]u8, endian: Endian) T

Parameters

T: typebuffer: *const [@divExact(@typeInfo(T).int.bits, 8)]u8endian: Endian

Example

 test readInt {
    try testing.expect(readInt(u0, &[_]u8{}, .big) == 0x0);
    try testing.expect(readInt(u0, &[_]u8{}, .little) == 0x0);

    try testing.expect(readInt(u8, &[_]u8{0x32}, .big) == 0x32);
    try testing.expect(readInt(u8, &[_]u8{0x12}, .little) == 0x12);

    try testing.expect(readInt(u16, &[_]u8{ 0x12, 0x34 }, .big) == 0x1234);
    try testing.expect(readInt(u16, &[_]u8{ 0x12, 0x34 }, .little) == 0x3412);

    try testing.expect(readInt(u72, &[_]u8{ 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0, 0x24 }, .big) == 0x123456789abcdef024);
    try testing.expect(readInt(u72, &[_]u8{ 0xec, 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0xfe }, .little) == 0xfedcba9876543210ec);

    try testing.expect(readInt(i8, &[_]u8{0xff}, .big) == -1);
    try testing.expect(readInt(i8, &[_]u8{0xfe}, .little) == -2);

    try testing.expect(readInt(i16, &[_]u8{ 0xff, 0xfd }, .big) == -3);
    try testing.expect(readInt(i16, &[_]u8{ 0xfc, 0xff }, .little) == -4);

    try moreReadIntTests();
    try comptime moreReadIntTests();
}

Source

  pub inline fn readInt(comptime T: type, buffer: *const [@divExact(@typeInfo(T).int.bits, 8)]u8, endian: Endian) T {
    const value: T = @bitCast(buffer.*);
    return if (endian == native_endian) value else @byteSwap(value);
}  