fix cmd/tools/vtest.v build

This PR enables building them again with v2, by making vlib/sync/pool.v
single threaded for now, and by removing the use of generics till they
are fixed in v2.

vlib/sync/pool.v

@@ -98,9 +98,10 @@ pub fn (pool mut PoolProcessor) set_max_jobs(njobs int) {
 // by the number of available cores on the system.
 // work_on_items returns *after* all threads finish.
 // You can optionally call get_results after that.
-pub fn (pool mut PoolProcessor) work_on_items<T>(items []T) {
-	pool.work_on_pointers( items.pointers() )
-}
+// TODO: uncomment, when generics work again
+//pub fn (pool mut PoolProcessor) work_on_items<T>(items []T) {
+//	pool.work_on_pointers( items.pointers() )
+//}
 
 pub fn (pool mut PoolProcessor) work_on_pointers(items []voidptr) {
 	mut njobs := runtime.nr_jobs()
@@ -115,7 +116,9 @@ pub fn (pool mut PoolProcessor) work_on_pointers(items []voidptr) {
 	pool.thread_contexts << [voidptr(0)].repeat(pool.items.len)
 	pool.waitgroup.add(njobs)
 	for i := 0; i < njobs; i++ {
-		go process_in_thread(pool,i)
+		// TODO: uncomment when `go func()` works again with v2
+		// go process_in_thread(pool,i)
+		process_in_thread(pool,i)
 	}
 	pool.waitgroup.wait()
 }
@@ -145,36 +148,44 @@ fn process_in_thread(pool mut PoolProcessor, task_id int) {
 
 // get_item - called by the worker callback.
 // Retrieves a type safe instance of the currently processed item
-pub fn (pool &PoolProcessor) get_item<T>(idx int) T {
-	return *(&T(pool.items[idx]))
-}
+// TODO: uncomment, when generics work again
+//pub fn (pool &PoolProcessor) get_item<T>(idx int) T {
+//	return *(&T(pool.items[idx]))
+//}
 
+// TODO: the below is a hack, remove it when v2 &string() casting works again
+type mystring string
 // get_string_item - called by the worker callback.
 // It does not use generics so it does not mess up vfmt.
 // TODO: remove the need for this when vfmt becomes smarter.
 pub fn (pool &PoolProcessor) get_string_item(idx int) string {
-	return *(&string(pool.items[idx]))
+   // return *(&string(pool.items[idx]))
+   // TODO: the below is a hack, remove it when v2 casting works again
+   return &mystring( pool.items[idx] )
 }
 
 // get_int_item - called by the worker callback.
 // It does not use generics so it does not mess up vfmt.
 // TODO: remove the need for this when vfmt becomes smarter.
 pub fn (pool &PoolProcessor) get_int_item(idx int) int {
-	return *(&int(pool.items[idx]))
+	item := pool.items[idx]
+	return *(&int(item))
 }
 
-pub fn (pool &PoolProcessor) get_result<T>(idx int) T {
-	return *(&T(pool.results[idx]))
-}
+// TODO: uncomment, when generics work again
+//pub fn (pool &PoolProcessor) get_result<T>(idx int) T {
+//	return *(&T(pool.results[idx]))
+//}
 
+// TODO: uncomment, when generics work again
 // get_results - can be called to get a list of type safe results.
-pub fn (pool &PoolProcessor) get_results<T>() []T {
-	mut res := []T
-	for i in 0 .. pool.results.len {
-		res << *(&T(pool.results[i]))
-	}
-	return res
-}
+//pub fn (pool &PoolProcessor) get_results<T>() []T {
+//	mut res := []T
+//	for i in 0 .. pool.results.len {
+//		res << *(&T(pool.results[i]))
+//	}
+//	return res
+//}
 
 // set_shared_context - can be called during the setup so that you can
 // provide a context that is shared between all worker threads, like
@@ -203,3 +214,38 @@ pub fn (pool mut PoolProcessor) set_thread_context(idx int, context voidptr) {
 pub fn (pool &PoolProcessor) get_thread_context(idx int) voidptr {
 	return pool.thread_contexts[idx]
 }
+
+// TODO: remove everything below this line after generics are fixed:
+pub struct SResult {
+pub:   
+	s string
+}
+pub struct IResult {
+pub:   
+	i int
+}
+
+//
+
+pub fn (pool mut PoolProcessor) work_on_items_s(items []string) {
+	pool.work_on_pointers( items.pointers() )
+}
+
+pub fn (pool mut PoolProcessor) work_on_items_i(items []int) {
+	pool.work_on_pointers( items.pointers() )
+}
+
+pub fn (pool &PoolProcessor) get_results_s() []SResult {
+	mut res := []SResult
+	for i in 0 .. pool.results.len {
+		res << *(&SResult(pool.results[i]))
+	}
+	return res
+}
+pub fn (pool &PoolProcessor) get_results_i() []IResult {
+	mut res := []IResult
+	for i in 0 .. pool.results.len {
+		res << *(&IResult(pool.results[i]))
+	}
+	return res
+}