::move ternary

gistfile1.txt

See related discussions:
* https://github.com/bitcoin/bitcoin/pull/28280#discussion_r1676800505
* https://github.com/bitcoin/bitcoin/pull/28280#discussion_r1676801434
* https://github.com/bitcoin/bitcoin/pull/17487#discussion_r402037193

```diff
---
diff --git a/src/test/coins_tests.cpp b/src/test/coins_tests.cpp
--- a/src/test/coins_tests.cpp	(revision 9f3bf64d29c497fb90406974548a717ba5918b25)
+++ b/src/test/coins_tests.cpp	(date 1723646168861)
@@ -1114,4 +1114,33 @@
     PoolResourceTester::CheckAllDataAccountedFor(resource);
 }
 
+void test_move_and_copy(bool move_condition) {
+    Coin coin1, coin2;
+    std::cout << "\nTesting " << (move_condition ? "Move" : "Copy") << " operations:\n";
+    std::cout << "----------------------------------------\n";
+
+    std::cout << "1. Using if-else statement:\n";
+    if (move_condition) {
+        coin1 = std::move(coin2);
+    } else {
+        coin1 = coin2;
+    }
+
+    std::cout << "\n2. Using ternary operator with direct move:\n";
+    coin1 = move_condition ? std::move(coin2) : coin2;
+
+    std::cout << "\n3. Using ternary with parenthesized assignments:\n";
+    move_condition ? (coin1 = std::move(coin2)) : (coin1 = coin2);
+
+    std::cout << "----------------------------------------\n";
+}
+
+BOOST_AUTO_TEST_CASE(move_is_used)
+{
+    bool move_condition = FastRandomContext().randbool();
+
+    test_move_and_copy(move_condition);
+    test_move_and_copy(!move_condition);
+}
+
 BOOST_AUTO_TEST_SUITE_END()

IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/src/coins.h b/src/coins.h
--- a/src/coins.h	(revision 9f3bf64d29c497fb90406974548a717ba5918b25)
+++ b/src/coins.h	(date 1723646270511)
@@ -21,6 +21,7 @@
 
 #include <functional>
 #include <unordered_map>
+#include <iostream>
 
 /**
  * A UTXO entry.
@@ -42,8 +43,44 @@
     uint32_t nHeight : 31;
 
     //! construct a Coin from a CTxOut and height/coinbase information.
-    Coin(CTxOut&& outIn, int nHeightIn, bool fCoinBaseIn) : out(std::move(outIn)), fCoinBase(fCoinBaseIn), nHeight(nHeightIn) {}
-    Coin(const CTxOut& outIn, int nHeightIn, bool fCoinBaseIn) : out(outIn), fCoinBase(fCoinBaseIn),nHeight(nHeightIn) {}
+    Coin(CTxOut&& outIn, int nHeightIn, bool fCoinBaseIn) : out(std::move(outIn)), fCoinBase(fCoinBaseIn), nHeight(nHeightIn) {
+        std::cout << "CTxOut rvalue constructor\n";
+    }
+
+    Coin(const CTxOut& outIn, int nHeightIn, bool fCoinBaseIn) : out(outIn), fCoinBase(fCoinBaseIn), nHeight(nHeightIn) {
+        std::cout << "CTxOut lvalue constructor\n";
+    }
+
+    Coin(Coin&& other) noexcept {
+        out = std::move(other.out);
+        fCoinBase = other.fCoinBase;
+        nHeight = other.nHeight;
+        std::cout << "Move constructor\n";
+    }
+
+    Coin& operator=(Coin&& other) noexcept {
+        if (this != &other) {
+            out = std::move(other.out);
+            fCoinBase = other.fCoinBase;
+            nHeight = other.nHeight;
+            std::cout << "Move assignment\n";
+        }
+        return *this;
+    }
+
+    Coin(const Coin& other) noexcept : out(other.out), fCoinBase(other.fCoinBase), nHeight(other.nHeight) {
+        std::cout << "Copy constructor\n";
+    }
+
+    Coin& operator=(const Coin& other) noexcept {
+        if (this != &other) {
+            out = other.out;
+            fCoinBase = other.fCoinBase;
+            nHeight = other.nHeight;
+            std::cout << "Copy assignment\n";
+        }
+        return *this;
+    }
```


Applying the patch and running the new test:

```
Testing Copy operations:
----------------------------------------
1. Using if-else statement:
Copy assignment

2. Using ternary operator with direct move:
Copy constructor
Move assignment

3. Using ternary with parenthesized assignments:
Copy assignment
----------------------------------------

Testing Move operations:
----------------------------------------
1. Using if-else statement:
Move assignment

2. Using ternary operator with direct move:
Move constructor
Move assignment

3. Using ternary with parenthesized assignments:
Move assignment
----------------------------------------
```

i.e. `move_condition ? (coin1 = std::move(coin2)) : (coin1 = coin2)` behaves the same way as the explicit if expression.