Generalized application-defined scalar functions

appveyor.yml

@@ -107,7 +107,7 @@ for:
   install:
     - |-
       cd C:\Tools\vcpkg
-      git fetch --tags && git checkout 2023.10.19
+      git fetch --tags && git checkout 2023.11.20
       cd %APPVEYOR_BUILD_FOLDER%
       C:\Tools\vcpkg\bootstrap-vcpkg.bat -disableMetrics
       C:\Tools\vcpkg\vcpkg integrate install
@@ -140,7 +140,7 @@ for:
   install:
     - |-
       pushd $HOME/vcpkg
-      git fetch --tags && git checkout 2023.10.19
+      git fetch --tags && git checkout 2023.11.20
       popd
       $HOME/vcpkg/bootstrap-vcpkg.sh -disableMetrics
       $HOME/vcpkg/vcpkg integrate install --overlay-triplets=vcpkg/triplets
@@ -168,7 +168,7 @@ for:
   # using custom vcpkg triplets for building and linking dynamic dependent libraries
   install:
     - |-
-      git clone --depth 1 --branch 2023.10.19 https://github.com/microsoft/vcpkg.git $HOME/vcpkg
+      git clone --depth 1 --branch 2023.11.20 https://github.com/microsoft/vcpkg.git $HOME/vcpkg
       $HOME/vcpkg/bootstrap-vcpkg.sh -disableMetrics
       $HOME/vcpkg/vcpkg integrate install --overlay-triplets=vcpkg/triplets
       vcpkg install sqlite3[core,dbstat,math,json1,fts5] catch2 --overlay-triplets=vcpkg/triplets

dev/alias.h

@@ -1,13 +1,12 @@
 #pragma once
 
-#include <type_traits>  //  std::enable_if
-#include <utility>  //  std::index_sequence, std::make_index_sequence
+#include <type_traits>  //  std::enable_if, std::is_same, std::conditional
+#include <utility>  //  std::make_index_sequence, std::move
 #include <string>  //  std::string
 #include <sstream>  //  std::stringstream
-#include <algorithm>  //  std::copy_n
 
-#include "functional/cxx_universal.h"  //  ::size_t
 #include "functional/cxx_type_traits_polyfill.h"
+#include "functional/char_array_template.h"
 #include "type_traits.h"
 #include "alias_traits.h"
 #include "table_type_of.h"
@@ -16,29 +15,7 @@
 namespace sqlite_orm {
 
     namespace internal {
-
 #ifdef SQLITE_ORM_WITH_CPP20_ALIASES
-        /*
-         *  Helper class to facilitate user-defined string literal operator template
-         */
-        template<size_t N>
-        struct string_identifier_template {
-            static constexpr size_t size() {
-                return N - 1;
-            }
-
-            constexpr string_identifier_template(const char (&id)[N]) {
-                std::copy_n(id, N, this->id);
-            }
-
-            char id[N];
-        };
-
-        template<template<char...> class Alias, string_identifier_template t, size_t... Idx>
-        consteval auto to_alias(std::index_sequence<Idx...>) {
-            return Alias<t.id[Idx]...>{};
-        }
-
         template<class T>
         inline constexpr bool is_operator_argument_v<T, std::enable_if_t<orm_column_alias<T>>> = true;
 #endif
@@ -364,18 +341,18 @@ namespace sqlite_orm {
      *  Examples:
      *  constexpr auto z_alias = "z"_alias.for_<User>();
      */
-    template<internal::string_identifier_template t>
+    template<internal::char_array_template name>
     [[nodiscard]] consteval auto operator"" _alias() {
-        return internal::to_alias<internal::recordset_alias_builder, t>(std::make_index_sequence<t.size()>{});
+        return internal::explode_into<internal::recordset_alias_builder, name>(std::make_index_sequence<name.size()>{});
     }
 
     /** @short Create a column alias.
      *  column_alias<'a'[, ...]> from a string literal.
      *  E.g. "a"_col, "b"_col
      */
-    template<internal::string_identifier_template t>
+    template<internal::char_array_template name>
     [[nodiscard]] consteval auto operator"" _col() {
-        return internal::to_alias<internal::column_alias, t>(std::make_index_sequence<t.size()>{});
+        return internal::explode_into<internal::column_alias, name>(std::make_index_sequence<name.size()>{});
     }
 #endif
 }