Set c++ version to c++23

I followed @pennae's advice and moved the constructor definition of
`AttrName` from the header file `nixexpr.hh` to `nixexpr.cc`.

Change-Id: I733f56c25635b366b11ba332ccec38dd7444e793

1 files changed, 2 insertions, 2 deletions

diff --git a/src/libexpr/nixexpr.hh b/src/libexpr/nixexpr.hh
index d16281c39..4e857b321 100644
--- a/src/libexpr/nixexpr.hh
+++ b/src/libexpr/nixexpr.hh
@@ -30,8 +30,8 @@ struct AttrName
 {
     Symbol symbol;
     std::unique_ptr<Expr> expr;
-    AttrName(Symbol s) : symbol(s) {};
-    AttrName(std::unique_ptr<Expr> e) : expr(std::move(e)) {};
+    AttrName(Symbol s);
+    AttrName(std::unique_ptr<Expr> e);
 };
 
 typedef std::vector<AttrName> AttrPath;