[vm/ffi] Platform.isX64 function

[Sunbreak]

I'm working on https://github.com/woodemi/twaindsm.dart, and many scanner devices have only 32-bit driver

Could we have Platform.isX64 function, something like Platform.isWindows or kIsWeb, to determine coresponding 32-bit or 64-bit TWAINDSM.dll?

import 'dart:ffi';

const bool kIsX64 = sizeOf<Pointer>() == 8;

[lrhn]

Sounds like something which should be in the ffi libraries. (Also it should probably be related to the pointer size, not the underlying CPU architecture, so it works for ARM64 too.)
Would you need to distinguish x32 from x86 too?

[Sunbreak]

Sounds like something which should be in the ffi libraries. (Also it should probably be related to the pointer size, not the underlying CPU architecture, so it works for ARM64 too.)
Would you need to distinguish x32 from x86 too?

ffi would be fine. No need for x32 for now :)

[dcharkes]

We only want to add things to dart:ffi which cannot be built on top of dart:ffi.

const bool kIsX64 = sizeOf<Pointer>() == 8; could go into package:ffi.

@Sunbreak could you make a PR?

Something like ffi/lib/src/platform.dart:

/// Whether Dart is running in 32-bit mode.
final bool is32Bit = sizeOf<Pointer>() == 4;

/// Whether Dart is running in 64-bit mode.
final bool is64Bit = sizeOf<Pointer>() == 8;

@lrhn would you be so kind to suggest a nice API? 😄

@Sunbreak note that you're not actually detecting the host OS, you're detecting whether Dart is running in 64-bit mode. You can execute a 32-bit Dart SDK on 64 bit Windows, but you'll not be able to load any 64-bit DLLs.

[Sunbreak]

@Sunbreak note that you're not actually detecting the host OS, you're detecting whether Dart is running in 64-bit mode. You can execute a 32-bit Dart SDK on 64 bit Windows, but you'll not be able to load any 64-bit DLLs.

Yep. That's what I want to do