chore: Add a helper function fmtstr::as_quoted_str

docs/docs/noir/standard_library/fmtstr.md

@@ -10,4 +10,14 @@ title: fmtstr
 
 #include_code quoted_contents noir_stdlib/src/meta/format_string.nr rust
 
-Returns the format string contents (that is, without the leading and trailing double quotes) as a `Quoted` value.
+Returns the format string contents (that is, without the leading and trailing double quotes) as a `Quoted` value.
+
+### as_quoted_str
+
+#include_code as_quoted_str noir_stdlib/src/meta/format_string.nr rust
+
+Returns the format string contents (with the leading and trailing double quotes) as a `Quoted` string literal (not a format string literal).
+
+Example:
+
+#include_code as_quoted_str_test test_programs/compile_success_empty/comptime_fmt_strings/src/main.nr rust 

noir_stdlib/src/meta/format_string.nr

@@ -1,6 +1,16 @@
+use super::ctstring::AsCtString;
+
 impl<let N: u32, T> fmtstr<N, T> {
+    /// Returns the format string contents (that is, without the leading and trailing double quotes) as a `Quoted` value.
     #[builtin(fmtstr_quoted_contents)]
     // docs:start:quoted_contents
     pub comptime fn quoted_contents(self) -> Quoted {}
     // docs:end:quoted_contents
+
+    /// Returns the format string contents (with the leading and trailing double quotes) as a `Quoted` string literal (not a format string literal).
+    // docs:start:as_quoted_str
+    pub comptime fn as_quoted_str(self) -> Quoted {
+        // docs:end:as_quoted_str
+        self.as_ctstring().as_quoted_str()
+    }
 }

test_programs/compile_success_empty/comptime_fmt_strings/src/main.nr

@@ -15,6 +15,14 @@ fn main() {
 
     // Mainly test fmtstr::quoted_contents
     call!(glue(quote { hello }, quote { world }));
+
+    // docs:start:as_quoted_str_test
+    comptime {
+        let x = 1;
+        let f: str<_> = f"x = {x}".as_quoted_str!();
+        assert_eq(f, "x = 0x01");
+    }
+    // docs:end:as_quoted_str_test
 }
 
 comptime fn glue(x: Quoted, y: Quoted) -> Quoted {