Merge bitcoin/bitcoin#25714: univalue: Avoid std::string copies

fa095257511e53d7a593c6714724aafb484e6b6f univalue: string_view test (MacroFake)
1111c7e3f1f5c550f62016d71ccc518aafd97acf univalue: Avoid std::string copies (MacroFake)

Pull request description:

  This shouldn't matter too much, unless a really large string is pushed into a json struct, but I think it also clarifies the code.

ACKs for top commit:
  martinus:
    Code review ACK https://github.com/bitcoin/bitcoin/commit/fa095257511e53d7a593c6714724aafb484e6b6f
  aureleoules:
    reACK fa095257511e53d7a593c6714724aafb484e6b6f
  ryanofsky:
    Code review ACK fa095257511e53d7a593c6714724aafb484e6b6f

Tree-SHA512: 74c441912bd0b00cdb9ea7890121f71ae5d62a7594e7d29aa402c9e3f033710c5d3afb27a37c552e6513804b249aa37e375ce013a3db853a25d1fd7b6e6cd3a8

1 files changed, 6 insertions, 6 deletions

diff --git a/src/univalue/lib/univalue.cpp b/src/univalue/lib/univalue.cpp
index 4448981d3e..5aa39edb75 100644
--- a/src/univalue/lib/univalue.cpp
+++ b/src/univalue/lib/univalue.cpp
@@ -44,15 +44,15 @@ static bool validNumStr(const std::string& s)
     return (tt == JTOK_NUMBER);
 }
 
-void UniValue::setNumStr(const std::string& val_)
+void UniValue::setNumStr(std::string str)
 {
-    if (!validNumStr(val_)) {
-        throw std::runtime_error{"The string '" + val_ + "' is not a valid JSON number"};
+    if (!validNumStr(str)) {
+        throw std::runtime_error{"The string '" + str + "' is not a valid JSON number"};
     }
 
     clear();
     typ = VNUM;
-    val = val_;
+    val = std::move(str);
 }
 
 void UniValue::setInt(uint64_t val_)
@@ -82,11 +82,11 @@ void UniValue::setFloat(double val_)
     return setNumStr(oss.str());
 }
 
-void UniValue::setStr(const std::string& val_)
+void UniValue::setStr(std::string str)
 {
     clear();
     typ = VSTR;
-    val = val_;
+    val = std::move(str);
 }
 
 void UniValue::setArray()