From 1d30d47b9a42088d9b382a8ba421a855bbdaa9b2 Mon Sep 17 00:00:00 2001
From: Ichthyostega <prg@ichthyostega.de>
Date: Fri, 29 Sep 2023 18:45:47 +0200
Subject: [PATCH] Library: add a simple usage for clarity

---
 src/lib/iter-explorer.hpp             | 24 +++++++++++++++++
 src/lib/scoped-collection.hpp         |  6 +++++
 tests/library/thread-wrapper-test.cpp | 39 ++++++++++++++++++++++++++-
 3 files changed, 68 insertions(+), 1 deletion(-)

diff --git a/src/lib/iter-explorer.hpp b/src/lib/iter-explorer.hpp
index c60867712..9e2323574 100644
--- a/src/lib/iter-explorer.hpp
+++ b/src/lib/iter-explorer.hpp
@@ -1647,6 +1647,30 @@ namespace lib {
           return IterExplorer::reduce ([](const reference val){ return val; });
         }
       
+      /** simplified _terminal builder_ to check if any result yields `true` (short-circuit) */
+      bool
+      has_any()
+        {
+          static_assert (std::is_constructible<bool,value_type>());
+          SRC& pipeline = *this;
+          for ( ; pipeline; ++pipeline)
+            if (*pipeline)
+              return true;
+          return false;
+        }
+      
+      /** simplified _terminal builder_ to check if all results yields `true` (short-circuit) */
+      bool
+      and_all()
+        {
+          static_assert (std::is_constructible<bool,value_type>());
+          SRC& pipeline = *this;
+          for ( ; pipeline; ++pipeline)
+            if (not *pipeline)
+              return false;
+          return true;
+        }
+      
       
       /** _terminal builder_ to pour and materialise all results from this Pipeline.
        * @tparam CON a STL compliant container to store generated values (defaults to `vector`)
diff --git a/src/lib/scoped-collection.hpp b/src/lib/scoped-collection.hpp
index 4be262287..a6eae5b58 100644
--- a/src/lib/scoped-collection.hpp
+++ b/src/lib/scoped-collection.hpp
@@ -350,6 +350,12 @@ namespace lib {
       bool    empty ()       const { return 0 == level_; }
       
       
+      // use in standard range for loops...
+      friend iterator       begin (ScopedCollection& sco)      { return sco.begin(); }
+      friend const iterator begin (ScopedCollection const& sco){ return sco.begin(); }
+      friend iterator       end   (ScopedCollection& sco)      { return sco.end(); }
+      friend const iterator end   (ScopedCollection const& sco){ return sco.end(); }
+      
       
     private:
       /* ==== Storage: heap allocated array of element buffers ==== */
diff --git a/tests/library/thread-wrapper-test.cpp b/tests/library/thread-wrapper-test.cpp
index 00d4ead0c..32fd48566 100644
--- a/tests/library/thread-wrapper-test.cpp
+++ b/tests/library/thread-wrapper-test.cpp
@@ -26,12 +26,18 @@
 
 
 #include "lib/test/run.hpp"
+#include "lib/test/test-helper.hpp"///////////TODO
 #include "lib/thread.hpp"
+#include "lib/iter-explorer.hpp"
 #include "lib/scoped-collection.hpp"
 
+#include <atomic>
 #include <chrono>
 
 using test::Test;
+using lib::explore;
+using std::atomic_uint;
+using std::this_thread::yield;
 using std::this_thread::sleep_for;
 using std::chrono::microseconds;
 
@@ -84,6 +90,36 @@ namespace lib {
         
         virtual void
         run (Arg)
+          {
+            demonstrateSimpleUsage();
+            verifyConcurrentExecution();
+          }
+        
+        /**
+         * @test demonstrate simple usage of the thread-wrapper
+         */ 
+        void
+        demonstrateSimpleUsage()
+          {
+            lib::ScopedCollection<Thread> threads{NUM_THREADS};
+            
+            atomic_uint invocations{0};
+            for (uint i=0; i<NUM_THREADS; ++i)
+              threads.emplace<Thread> ("counter"
+                                      ,[&]{ ++invocations; });
+            
+            while (explore(threads).has_any())
+              yield();
+            
+            CHECK (invocations == NUM_THREADS);
+          }
+        
+        
+        /**
+         * @test verify the thread function is actually performed concurrently
+         */
+        void
+        verifyConcurrentExecution()
           {
             lib::ScopedCollection<TestThread> threads{NUM_THREADS};
             
@@ -95,7 +131,8 @@ namespace lib {
                 threads.emplace<TestThread> (&TestThread::doIt, uint{i}, uint{x});
               }
             
-            usleep (200000);  // pause 200ms for the threads to terminate.....
+            while (explore(threads).has_any())
+              yield();
             
             size_t checkSum = 0;
             for (auto& t : threads)