From ee50ed08c2e72b90115468368a8ee3fb061ce486 Mon Sep 17 00:00:00 2001
From: Francisco Paisana <paisanaf@tcd.ie>
Date: Tue, 14 Apr 2020 13:21:35 +0100
Subject: [PATCH] allow inplace task to be called in const contexts

---
 lib/include/srslte/common/inplace_task.h | 6 +++---
 lib/test/common/queue_test.cc            | 7 +++++++
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/lib/include/srslte/common/inplace_task.h b/lib/include/srslte/common/inplace_task.h
index f0d0ec215..d7bf563dc 100644
--- a/lib/include/srslte/common/inplace_task.h
+++ b/lib/include/srslte/common/inplace_task.h
@@ -155,7 +155,7 @@ public:
     return *this;
   }
 
-  R operator()(Args&&... args) { return oper_ptr->call(&buffer, std::forward<Args>(args)...); }
+  R operator()(Args&&... args) const { return oper_ptr->call(&buffer, std::forward<Args>(args)...); }
 
   bool is_empty() const { return oper_ptr == oper_table_t::get_empty(); }
   bool is_in_small_buffer() const { return oper_ptr->is_in_buffer; }
@@ -188,8 +188,8 @@ public:
 
 private:
   union {
-    storage_t buffer;
-    void*     ptr;
+    mutable storage_t buffer;
+    void*             ptr;
   };
   const oper_table_t* oper_ptr;
 };
diff --git a/lib/test/common/queue_test.cc b/lib/test/common/queue_test.cc
index 25000fe5a..5f0f562a8 100644
--- a/lib/test/common/queue_test.cc
+++ b/lib/test/common/queue_test.cc
@@ -390,6 +390,13 @@ int test_inplace_task()
   t2();
   TESTASSERT(v == 5);
 
+  // TEST: task works in const contexts
+  t       = l2;
+  auto l3 = [](const srslte::inplace_task<void()>& task) { task(); };
+  v       = 0;
+  l3(t);
+  TESTASSERT(v == 6);
+
   std::cout << "outcome: Success\n";
   std::cout << "========================================\n";
   return 0;