From d466b810cf504a6fce9b6412ce5d52a0cce080ae Mon Sep 17 00:00:00 2001
From: Ben Deane <ben@elbeno.com>
Date: Thu, 22 Oct 2026 14:27:51 -0600
Subject: [PATCH] :art: Recognize shrunk types and values in formatting and
 expand them

Problem:
- It is annoying to manually expand shrunk items for formatting.

Solution:
- Allow them to be automatically expanded when formatted.
---
 include/stdx/ct_format.hpp |  6 +++---
 test/ct_format.cpp         | 25 +++++++++++++++++++++++++
 2 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/include/stdx/ct_format.hpp b/include/stdx/ct_format.hpp
index 6f9c567..bffcbe4 100644
--- a/include/stdx/ct_format.hpp
+++ b/include/stdx/ct_format.hpp
@@ -235,12 +235,12 @@ consteval auto arg_value(std::integral_constant<T, V>) {
     if constexpr (std::is_enum_v<T>) {
         return enum_as_string<V>();
     } else {
-        return V;
+        return expand(V);
     }
 }
 
 template <typename T> consteval auto arg_value(type_identity<T>) {
-    return type_as_string<T>();
+    return type_as_string<expand_t<T>>();
 }
 
 template <ct_string S> consteval auto arg_value(cts_t<S>) { return S; }
@@ -255,7 +255,7 @@ consteval auto arg_value(fmt_cx_value auto a) {
     } else if constexpr (std::is_enum_v<decltype(a())>) {
         return enum_as_string<a()>();
     } else {
-        return a();
+        return expand(a());
     }
 }
 
diff --git a/test/ct_format.cpp b/test/ct_format.cpp
index 01b890b..9491453 100644
--- a/test/ct_format.cpp
+++ b/test/ct_format.cpp
@@ -68,6 +68,13 @@ TEST_CASE("format a compile-time stringish argument (CX_VALUE)",
                    "Hello world"_fmt_res);
 }
 
+TEST_CASE("format a shrunk compile-time stringish argument (CX_VALUE)",
+          "[ct_format]") {
+    using namespace std::string_view_literals;
+    STATIC_REQUIRE(stdx::ct_format<"Hello {}">(CX_VALUE(
+                       stdx::shrink<"world">())) == "Hello world"_fmt_res);
+}
+
 TEST_CASE("format a compile-time stringish argument (ct)", "[ct_format]") {
     using namespace std::string_view_literals;
     STATIC_REQUIRE(stdx::ct_format<"Hello {}">("world"_ctst) ==
@@ -76,6 +83,14 @@ TEST_CASE("format a compile-time stringish argument (ct)", "[ct_format]") {
                    "Hello world"_fmt_res);
 }
 
+TEST_CASE("format a shrunk compile-time stringish argument (ct)",
+          "[ct_format]") {
+    using namespace std::string_view_literals;
+    STATIC_REQUIRE(
+        stdx::ct_format<"Hello {}">(stdx::ct<stdx::shrink<"world">()>()) ==
+        "Hello world"_fmt_res);
+}
+
 TEST_CASE("format a compile-time integral argument (CX_VALUE)", "[ct_format]") {
     STATIC_REQUIRE(stdx::ct_format<"Hello {}">(CX_VALUE(42)) ==
                    "Hello 42"_fmt_res);
@@ -139,11 +154,21 @@ TEST_CASE("format a type argument (CX_VALUE)", "[ct_format]") {
                    "Hello int"_fmt_res);
 }
 
+TEST_CASE("format a shrunk type argument (CX_VALUE)", "[ct_format]") {
+    STATIC_REQUIRE(stdx::ct_format<"Hello {}">(CX_VALUE(stdx::shrink_t<int>)) ==
+                   "Hello int"_fmt_res);
+}
+
 TEST_CASE("format a type argument (ct)", "[ct_format]") {
     STATIC_REQUIRE(stdx::ct_format<"Hello {}">(stdx::ct<int>()) ==
                    "Hello int"_fmt_res);
 }
 
+TEST_CASE("format a shrunk type argument (ct)", "[ct_format]") {
+    STATIC_REQUIRE(stdx::ct_format<"Hello {}">(
+                       stdx::ct<stdx::shrink_t<int>>()) == "Hello int"_fmt_res);
+}
+
 TEST_CASE("format a compile-time argument with different base", "[ct_format]") {
     STATIC_REQUIRE(stdx::ct_format<"Hello 0x{:x}">(CX_VALUE(42)) ==
                    "Hello 0x2a"_fmt_res);