From 26f83b9efbb420fd859402620c56cd1e7dc1ae13 Mon Sep 17 00:00:00 2001
From: q66 <daniel@octaforge.org>
Date: Fri, 29 May 2015 20:02:40 +0100
Subject: [PATCH] pop_first() and pop_last() now return bool instead of void
 (true if popped, false if not)

---
 octa/algorithm.h |  9 +++++----
 octa/range.h     | 52 +++++++++++++++++++++++++++++-------------------
 2 files changed, 36 insertions(+), 25 deletions(-)

diff --git a/octa/algorithm.h b/octa/algorithm.h
index 056b60d..816a3b3 100644
--- a/octa/algorithm.h
+++ b/octa/algorithm.h
@@ -440,8 +440,8 @@ namespace octa {
         bool empty() const { return p_range.empty(); }
         RangeSize<T> size() const { return p_range.size(); }
 
-        void pop_first() { p_range.pop_first(); }
-        void pop_last() { p_range.pop_last(); }
+        bool pop_first() { return p_range.pop_first(); }
+        bool pop_last() { return p_range.pop_last(); }
 
         bool push_first() { return p_range.pop_first(); }
         bool push_last() { return p_range.push_last(); }
@@ -530,9 +530,10 @@ namespace octa {
 
         bool empty() const { return p_range.empty(); }
 
-        void pop_first() {
-            p_range.pop_first();
+        bool pop_first() {
+            bool ret = p_range.pop_first();
             advance_valid();
+            return ret;
         }
         bool push_first() {
             T tmp = p_range;
diff --git a/octa/range.h b/octa/range.h
index cd57faa..6d746e2 100644
--- a/octa/range.h
+++ b/octa/range.h
@@ -120,19 +120,15 @@ namespace octa {
 
     template<typename R>
     RangeSize<R> __octa_pop_first_n(R &range, RangeSize<R> n) {
-        for (RangeSize<R> i = 0; i < n; ++i) {
-            if (range.empty()) return i;
-            range.pop_first();
-        }
+        for (RangeSize<R> i = 0; i < n; ++i)
+            if (!range.pop_first()) return i;
         return n;
     }
 
     template<typename R>
     RangeSize<R> __octa_pop_last_n(R &range, RangeSize<R> n) {
-        for (RangeSize<R> i = 0; i < n; ++i) {
-            if (range.empty()) return i;
-            range.pop_last();
-        }
+        for (RangeSize<R> i = 0; i < n; ++i)
+            if (!range.pop_last()) return i;
         return n;
     }
 
@@ -237,8 +233,8 @@ namespace octa {
         bool empty() const { return p_range.empty(); }
         r_size size() const { return p_range.size(); }
 
-        void pop_first() { p_range.pop_last(); }
-        void pop_last() { p_range.pop_first(); }
+        bool pop_first() { return p_range.pop_last(); }
+        bool pop_last() { return p_range.pop_first(); }
 
         bool push_first() { return p_range.push_last(); }
         bool push_last() { return p_range.push_first(); }
@@ -316,8 +312,8 @@ namespace octa {
         bool empty() const { return p_range.empty(); }
         r_size size() const { return p_range.size(); }
 
-        void pop_first() { p_range.pop_first(); }
-        void pop_last() { p_range.pop_last(); }
+        bool pop_first() { return p_range.pop_first(); }
+        bool pop_last() { return p_range.pop_last(); }
 
         bool push_first() { return p_range.push_first(); }
         bool push_last() { return p_range.push_last(); }
@@ -370,7 +366,7 @@ namespace octa {
         }
 
         bool empty() const { return p_a * p_step >= p_b * p_step; }
-        void pop_first() { p_a += p_step; }
+        bool pop_first() { p_a += p_step; return true; }
         bool push_first() { p_a -= p_step; return true; }
         T &first() { return p_a; }
 
@@ -412,9 +408,10 @@ namespace octa {
         /* satisfy InputRange / ForwardRange */
         bool empty() const { return p_beg == p_end; }
 
-        void pop_first() {
-            if (p_beg == p_end) return;
+        bool pop_first() {
+            if (p_beg == p_end) return false;
             ++p_beg;
+            return true;
         }
         bool push_first() {
             --p_beg; return true;
@@ -439,9 +436,10 @@ namespace octa {
         const T &first() const { return *p_beg; }
 
         /* satisfy BidirectionalRange */
-        void pop_last() {
-            if (p_end == p_beg) return;
+        bool pop_last() {
+            if (p_end == p_beg) return false;
             --p_end;
+            return true;
         }
         bool push_last() {
             ++p_end; return true;
@@ -540,7 +538,13 @@ namespace octa {
 
         bool empty() const { return p_range.empty(); }
 
-        void pop_first() { ++p_index; p_range.pop_first(); }
+        bool pop_first() {
+            if (p_range.pop_first()) {
+                ++p_index;
+                return true;
+            }
+            return false;
+        }
 
         r_size pop_first_n(r_size n) {
             r_size ret = p_range.pop_first_n(n);
@@ -597,7 +601,13 @@ namespace octa {
 
         bool empty() const { return (p_remaining <= 0) || p_range.empty(); }
 
-        void pop_first() { --p_remaining; p_range.pop_first(); }
+        bool pop_first() {
+            if (p_range.pop_first()) {
+                --p_remaining;
+                return true;
+            }
+            return false;
+        }
         bool push_first() {
             if (p_range.push_first()) {
                 ++p_remaining;
@@ -632,7 +642,7 @@ namespace octa {
         void pop_last() {
             static_assert(IsRandomAccessRange<T>::value,
                 "pop_last() only available for random access ranges");
-            --p_remaining;
+            return --p_remaining >= 0;
         }
         RangeSize<T> pop_last_n(RangeSize<T> n) {
             static_assert(IsRandomAccessRange<T>::value,
@@ -706,7 +716,7 @@ namespace octa {
         }
 
         bool empty() const { return p_range.empty(); }
-        void pop_first() { p_range.pop_first_n(p_chunksize); }
+        bool pop_first() { return p_range.pop_first_n(p_chunksize) > 0; }
         bool push_first() {
             T tmp = p_range;
             RangeSize<T> an = tmp.push_first_n(p_chunksize);