Add docs; Update function to return error instead of throwing; Format…

…ting;

docs/docs/icicle/programmers_guide/cpp.md

@@ -32,6 +32,21 @@ eIcicleError result = icicle_set_device(device);
 eIcicleError result = icicle_get_active_device(device);
 ```
 
+### Setting and Getting the Default Device
+
+You can set the default device for all threads:
+
+```cpp
+icicle::Device device = {"CUDA", 0}; // or other
+eIcicleError result = icicle_set_default_device(device);
+```
+
+:::caution
+
+Setting a default device should be done **once** from the main thread of the application. If another device or backend is needed for a specific thread [icicle_set_device](#setting-and-getting-active-device) should be used instead.
+
+:::
+
 ### Querying Device Information
 
 Retrieve the number of available devices and check if a pointer is allocated on the host or on the active device:

docs/docs/icicle/programmers_guide/general.md

@@ -85,6 +85,7 @@ ICICLE provides a device abstraction layer that allows you to interact with diff
 
 - **Loading Backends**: Backends are loaded dynamically based on the environment configuration or a specified path.
 - **Setting Active Device**: The active device for a thread can be set, allowing for targeted computation on a specific device.
+- **Setting Default Device**: The default device for any thread without an active device can be set, removing the need to specify an alternative device on each thread. This is especially useful when running on a backend that is not the built-in CPU backend which is the default device to start.
 
 ## Streams
 

docs/docs/icicle/programmers_guide/go.md

@@ -27,12 +27,27 @@ result := runtime.LoadBackend("/path/to/backend/installdir", true)
 You can set the active device for the current thread and retrieve it when needed:
 
 ```go
-device = runtime.CreateDevice("CUDA", 0) // or other
+device := runtime.CreateDevice("CUDA", 0) // or other
 result := runtime.SetDevice(device)
 // or query current (thread) device 
 activeDevice := runtime.GetActiveDevice()
 ```
 
+### Setting and Getting the Default Device
+
+You can set the default device for all threads:
+
+```go
+device := runtime.CreateDevice("CUDA", 0) // or other
+defaultDevice := runtime.SetDefaultDevice(device);
+```
+
+:::caution
+
+Setting a default device should be done **once** from the main thread of the application. If another device or backend is needed for a specific thread [runtime.SetDevice](#setting-and-getting-active-device) should be used instead.
+
+:::
+
 ### Querying Device Information
 
 Retrieve the number of available devices and check if a pointer is allocated on the host or on the active device:

docs/docs/icicle/programmers_guide/rust.md

@@ -55,6 +55,21 @@ icicle_runtime::set_device(&device).unwrap();
 let active_device = icicle_runtime::get_active_device().unwrap();
 ```
 
+### Setting and Getting the Default Device
+
+You can set the default device for all threads:
+
+```caution
+let device = Device::new("CUDA", 0); // or other
+let default_device = icicle_runtime::set_default_device(device);
+```
+
+:::note
+
+Setting a default device should be done **once** from the main thread of the application. If another device or backend is needed for a specific thread [icicle_runtime::set_device](#setting-and-getting-active-device) should be used instead.
+
+:::
+
 ### Querying Device Information
 
 Retrieve the number of available devices and check if a pointer is allocated on the host or on the active device:

examples/c++/best-practice-ntt/example.cpp

@@ -116,8 +116,8 @@ int main(int argc, char* argv[])
   // Clean-up
   for (int i = 0; i < 2; i++) {
     ICICLE_CHECK(icicle_free(d_vec[i]));
-    delete[](h_inp[i]);
-    delete[](h_out[i]);
+    delete[] (h_inp[i]);
+    delete[] (h_out[i]);
   }
   ICICLE_CHECK(icicle_destroy_stream(stream_compute));
   ICICLE_CHECK(icicle_destroy_stream(stream_d2h));

icicle/src/device_api.cpp

@@ -61,9 +61,10 @@ namespace icicle {
     eIcicleError set_default_device(const Device& dev)
     {
       if (!is_device_registered(dev.type)) {
-        THROW_ICICLE_ERR(
-          eIcicleError::INVALID_DEVICE, "Device type " + std::string(dev.type) + " has not been registered");
+        ICICLE_LOG_ERROR << "Device type " + std::string(dev.type) + " is not valid as it has not been registered";
+        return eIcicleError::INVALID_DEVICE;
       }
+
       m_default_device = dev;
       return eIcicleError::SUCCESS;
     }