More compact, yet still awkward loop counter update

Author: rhornung67

src/basic/DAXPY-Seq.cpp

@@ -37,10 +37,8 @@ void DAXPY::runSeqVariant(VariantID vid, size_t RAJAPERF_UNUSED_ARG(tune_idx))
     case Base_Seq : {
 
       startTimer();
-      // Standalone assignment expression for loop counter to quiet
-      // C++20 compiler warning 
-      for (RepIndex_type irep = 0; irep < run_reps; /* no update here */) {
-        irep = irep + 1;
+      // Awkward expression for loop counter quiets C++20 compiler warning 
+      for (RepIndex_type irep = 0; irep < run_reps; ((irep = irep + 1), 0)) {
 
         for (Index_type i = ibegin; i < iend; ++i ) {
           DAXPY_BODY;
@@ -56,10 +54,8 @@ void DAXPY::runSeqVariant(VariantID vid, size_t RAJAPERF_UNUSED_ARG(tune_idx))
     case Lambda_Seq : {
 
       startTimer();
-      // Standalone assignment expression for loop counter to quiet
-      // C++20 compiler warning 
-      for (RepIndex_type irep = 0; irep < run_reps; /* no update here */) {
-        irep = irep + 1;
+      // Awkward expression for loop counter quiets C++20 compiler warning  
+      for (RepIndex_type irep = 0; irep < run_reps; ((irep = irep + 1), 0)) {
 
         for (Index_type i = ibegin; i < iend; ++i ) {
           daxpy_lam(i);
@@ -76,10 +72,8 @@ void DAXPY::runSeqVariant(VariantID vid, size_t RAJAPERF_UNUSED_ARG(tune_idx))
       auto res{getHostResource()};
 
       startTimer();
-      // Standalone assignment expression for loop counter to quiet
-      // C++20 compiler warning 
-      for (RepIndex_type irep = 0; irep < run_reps; /* no update here */) {
-        irep = irep + 1;
+      // Awkward expression for loop counter quiets C++20 compiler warning  
+      for (RepIndex_type irep = 0; irep < run_reps; ((irep = irep + 1), 0)) {
 
         RAJA::forall<RAJA::seq_exec>( res,
           RAJA::RangeSegment(ibegin, iend), daxpy_lam);