From d41a45b008a9818501e9f5382a967b36120a2561 Mon Sep 17 00:00:00 2001
From: Daniel Falbel <dfalbel@gmail.com>
Date: Mon, 14 Aug 2023 15:42:15 -0300
Subject: [PATCH] Raise error when comparing a device with something that's not
 a dtype.

---
 R/dtype.R                   | 3 +++
 tests/testthat/test-dtype.R | 9 +++++++++
 2 files changed, 12 insertions(+)

diff --git a/R/dtype.R b/R/dtype.R
index f88f74a09e..3871a0af72 100644
--- a/R/dtype.R
+++ b/R/dtype.R
@@ -147,6 +147,9 @@ torch_qint32 <- function() torch_dtype$new(cpp_torch_qint32())
 
 #' @export
 `==.torch_dtype` <- function(e1, e2) {
+  if (!is_torch_dtype(e1) || !is_torch_dtype(e2)) {
+    runtime_error("One of the objects is not a dtype. Comparison is not possible.")
+  }
   cpp_dtype_to_string(e1$ptr) == cpp_dtype_to_string(e2$ptr)
 }
 
diff --git a/tests/testthat/test-dtype.R b/tests/testthat/test-dtype.R
index 635d77f2a6..30af649bce 100644
--- a/tests/testthat/test-dtype.R
+++ b/tests/testthat/test-dtype.R
@@ -66,3 +66,12 @@ test_that("can set select devices using strings", {
   }
   
 })
+
+test_that("error when comparing dtypes", {
+  
+  expect_error(
+    NULL == torch_float64(),
+    "not a dtype"
+  )
+  
+})
\ No newline at end of file