ExpectedT factory class

16 files changed, 221 insertions, 128 deletions

diff --git a/toolsrc/include/LineInfo.h b/toolsrc/include/LineInfo.h
index 66d91c520..62973462a 100644
--- a/toolsrc/include/LineInfo.h
+++ b/toolsrc/include/LineInfo.h
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <string>
+
 namespace vcpkg
 {
     struct LineInfo
diff --git a/toolsrc/include/PackageSpec.h b/toolsrc/include/PackageSpec.h
index 050d9d079..58edb8274 100644
--- a/toolsrc/include/PackageSpec.h
+++ b/toolsrc/include/PackageSpec.h
@@ -7,9 +7,11 @@ namespace vcpkg
 {
     struct PackageSpec
     {
-        static Expected<PackageSpec> from_string(const std::string& spec_as_string, const Triplet& default_triplet);
+        static ExpectedT<PackageSpec, PackageSpecParseResult> from_string(const std::string& spec_as_string,
+                                                                          const Triplet& default_triplet);
         static std::string to_string(const std::string& name, const Triplet& triplet);
-        static Expected<PackageSpec> from_name_and_triplet(const std::string& name, const Triplet& triplet);
+        static ExpectedT<PackageSpec, PackageSpecParseResult> from_name_and_triplet(const std::string& name,
+                                                                                    const Triplet& triplet);
 
         const std::string& name() const;
 
diff --git a/toolsrc/include/PackageSpecParseResult.h b/toolsrc/include/PackageSpecParseResult.h
index b72c534c2..17d151626 100644
--- a/toolsrc/include/PackageSpecParseResult.h
+++ b/toolsrc/include/PackageSpecParseResult.h
@@ -1,5 +1,6 @@
 #pragma once
-#include <system_error>
+
+#include "vcpkg_expected.h"
 
 namespace vcpkg
 {
@@ -10,27 +11,21 @@ namespace vcpkg
         INVALID_CHARACTERS
     };
 
-    struct PackageSpecParseResultCategoryImpl final : std::error_category
-    {
-        virtual const char* name() const noexcept override;
+    CStringView to_string(PackageSpecParseResult ev) noexcept;
 
-        virtual std::string message(int ev) const noexcept override;
-    };
-
-    const std::error_category& package_spec_parse_result_category();
+    template<>
+    struct ErrorHolder<PackageSpecParseResult>
+    {
+        ErrorHolder() : m_err(PackageSpecParseResult::SUCCESS) {}
+        ErrorHolder(PackageSpecParseResult err) : m_err(err) {}
 
-    std::error_code make_error_code(PackageSpecParseResult e);
+        constexpr bool has_error() const { return m_err != PackageSpecParseResult::SUCCESS; }
 
-    PackageSpecParseResult to_package_spec_parse_result(int i);
+        PackageSpecParseResult error() const { return m_err; }
 
-    PackageSpecParseResult to_package_spec_parse_result(std::error_code ec);
-}
+        CStringView to_string() const { return vcpkg::to_string(m_err); }
 
-// Enable implicit conversion to std::error_code
-namespace std
-{
-    template<>
-    struct is_error_code_enum<vcpkg::PackageSpecParseResult> : ::std::true_type
-    {
+    private:
+        PackageSpecParseResult m_err;
     };
 }
diff --git a/toolsrc/include/Paragraphs.h b/toolsrc/include/Paragraphs.h
index 66f6bd2e4..59f0eefc8 100644
--- a/toolsrc/include/Paragraphs.h
+++ b/toolsrc/include/Paragraphs.h
@@ -16,7 +16,8 @@ namespace vcpkg::Paragraphs
     Expected<ParagraphDataMap> parse_single_paragraph(const std::string& str);
     Expected<std::vector<ParagraphDataMap>> parse_paragraphs(const std::string& str);
 
-    Expected<SourceParagraph> try_load_port(const Files::Filesystem& fs, const fs::path& control_path);
+    ExpectedT<SourceParagraph, ParseControlErrorInfo> try_load_port(const Files::Filesystem& fs,
+                                                                    const fs::path& control_path);
 
     Expected<BinaryParagraph> try_load_cached_package(const VcpkgPaths& paths, const PackageSpec& spec);
 
diff --git a/toolsrc/include/SourceParagraph.h b/toolsrc/include/SourceParagraph.h
index 19f558170..9874eb3a9 100644
--- a/toolsrc/include/SourceParagraph.h
+++ b/toolsrc/include/SourceParagraph.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include "vcpkg_expected.h"
 #include <unordered_map>
 #include <vector>
 
@@ -15,14 +16,23 @@ namespace vcpkg
 
     const std::string& to_string(const Dependency& dep);
 
+    struct ParseControlErrorInfo
+    {
+        std::string name;
+        std::string remaining_fields_as_string;
+        std::string valid_fields_as_string;
+        std::error_code error;
+    };
+
     /// <summary>
     /// Port metadata (CONTROL file)
     /// </summary>
     struct SourceParagraph
     {
-        SourceParagraph();
+        static ExpectedT<SourceParagraph, ParseControlErrorInfo> parse_control_file(
+            std::unordered_map<std::string, std::string> fields);
 
-        explicit SourceParagraph(std::unordered_map<std::string, std::string> fields);
+        SourceParagraph();
 
         std::string name;
         std::string version;
@@ -31,6 +41,9 @@ namespace vcpkg
         std::vector<Dependency> depends;
     };
 
+    void print_error_message(const ParseControlErrorInfo& info);
+    void print_error_message(std::vector<ParseControlErrorInfo> error_info_list);
+
     std::vector<std::string> filter_dependencies(const std::vector<Dependency>& deps, const Triplet& t);
 
     std::vector<Dependency> expand_qualified_dependencies(const std::vector<std::string>& depends);
diff --git a/toolsrc/include/vcpkg_expected.h b/toolsrc/include/vcpkg_expected.h
index 3a920022b..15dbf5e79 100644
--- a/toolsrc/include/vcpkg_expected.h
+++ b/toolsrc/include/vcpkg_expected.h
@@ -5,27 +5,63 @@
 
 namespace vcpkg
 {
-    template<class T>
-    class Expected
+    template<class Err>
+    struct ErrorHolder
     {
-    public:
-        // Constructors are intentionally implicit
-        Expected(const std::error_code& ec) : m_error_code(ec), m_t() {}
+        ErrorHolder() : m_is_error(false) {}
+        ErrorHolder(const Err& err) : m_is_error(true), m_err(err) {}
+        ErrorHolder(Err&& err) : m_is_error(true), m_err(std::move(err)) {}
+
+        constexpr bool has_error() const { return m_is_error; }
+
+        const Err& error() const { return m_err; }
+        Err& error() { return m_err; }
+
+        CStringView to_string() const { return "value was error"; }
+
+    private:
+        bool m_is_error;
+        Err m_err;
+    };
+
+    template<>
+    struct ErrorHolder<std::error_code>
+    {
+        ErrorHolder() = default;
+        ErrorHolder(const std::error_code& err) : m_err(err) {}
+
+        constexpr bool has_error() const { return bool(m_err); }
 
-        Expected(std::errc ec) : Expected(std::make_error_code(ec)) {}
+        const std::error_code& error() const { return m_err; }
+        std::error_code& error() { return m_err; }
 
-        Expected(const T& t) : m_error_code(), m_t(t) {}
+        CStringView to_string() const { return "value was error"; }
 
-        Expected(T&& t) : m_error_code(), m_t(std::move(t)) {}
+    private:
+        std::error_code m_err;
+    };
+
+    template<class T, class S>
+    class ExpectedT
+    {
+    public:
+        constexpr ExpectedT() = default;
+
+        // Constructors are intentionally implicit
+
+        ExpectedT(const S& s) : m_s(s) {}
+        ExpectedT(S&& s) : m_s(std::move(s)) {}
 
-        Expected() : Expected(std::error_code(), T()) {}
+        ExpectedT(const T& t) : m_t(t) {}
+        ExpectedT(T&& t) : m_t(std::move(t)) {}
 
-        Expected(const Expected&) = default;
-        Expected(Expected&&) = default;
-        Expected& operator=(const Expected&) = default;
-        Expected& operator=(Expected&&) = default;
+        ExpectedT(const ExpectedT&) = default;
+        ExpectedT(ExpectedT&&) = default;
+        ExpectedT& operator=(const ExpectedT&) = default;
+        ExpectedT& operator=(ExpectedT&&) = default;
 
-        std::error_code error_code() const { return this->m_error_code; }
+        explicit constexpr operator bool() const noexcept { return !m_s.has_error(); }
+        constexpr bool has_value() const noexcept { return !m_s.has_error(); }
 
         T&& value_or_exit(const LineInfo& line_info) &&
         {
@@ -39,9 +75,13 @@ namespace vcpkg
             return this->m_t;
         }
 
+        const S& error() const & { return this->m_s.error(); }
+
+        S&& error() && { return std::move(this->m_s.error()); }
+
         const T* get() const
         {
-            if (m_error_code)
+            if (!this->has_value())
             {
                 return nullptr;
             }
@@ -50,7 +90,7 @@ namespace vcpkg
 
         T* get()
         {
-            if (m_error_code)
+            if (!this->has_value())
             {
                 return nullptr;
             }
@@ -60,10 +100,13 @@ namespace vcpkg
     private:
         void exit_if_error(const LineInfo& line_info) const
         {
-            Checks::check_exit(line_info, !this->m_error_code, this->m_error_code.message());
+            Checks::check_exit(line_info, !m_s.has_error(), m_s.to_string());
         }
 
-        std::error_code m_error_code;
+        ErrorHolder<S> m_s;
         T m_t;
     };
+
+    template<class T>
+    using Expected = ExpectedT<T, std::error_code>;
 }
diff --git a/toolsrc/src/PackageSpec.cpp b/toolsrc/src/PackageSpec.cpp
index 69883a030..ab005f255 100644
--- a/toolsrc/src/PackageSpec.cpp
+++ b/toolsrc/src/PackageSpec.cpp
@@ -7,7 +7,8 @@ namespace vcpkg
 {
     static bool is_valid_package_spec_char(char c) { return (c == '-') || isdigit(c) || (isalpha(c) && islower(c)); }
 
-    Expected<PackageSpec> PackageSpec::from_string(const std::string& spec_as_string, const Triplet& default_triplet)
+    ExpectedT<PackageSpec, PackageSpecParseResult> PackageSpec::from_string(const std::string& spec_as_string,
+                                                                            const Triplet& default_triplet)
     {
         auto pos = spec_as_string.find(':');
         if (pos == std::string::npos)
@@ -18,7 +19,7 @@ namespace vcpkg
         auto pos2 = spec_as_string.find(':', pos + 1);
         if (pos2 != std::string::npos)
         {
-            return std::error_code(PackageSpecParseResult::TOO_MANY_COLONS);
+            return PackageSpecParseResult::TOO_MANY_COLONS;
         }
 
         const std::string name = spec_as_string.substr(0, pos);
@@ -26,11 +27,12 @@ namespace vcpkg
         return from_name_and_triplet(name, triplet);
     }
 
-    Expected<PackageSpec> PackageSpec::from_name_and_triplet(const std::string& name, const Triplet& triplet)
+    ExpectedT<PackageSpec, PackageSpecParseResult> PackageSpec::from_name_and_triplet(const std::string& name,
+                                                                                      const Triplet& triplet)
     {
         if (Util::find_if_not(name, is_valid_package_spec_char) != name.end())
         {
-            return std::error_code(PackageSpecParseResult::INVALID_CHARACTERS);
+            return PackageSpecParseResult::INVALID_CHARACTERS;
         }
 
         PackageSpec p;
diff --git a/toolsrc/src/PackageSpecParseResult.cpp b/toolsrc/src/PackageSpecParseResult.cpp
index 487c3aa1d..838c788ba 100644
--- a/toolsrc/src/PackageSpecParseResult.cpp
+++ b/toolsrc/src/PackageSpecParseResult.cpp
@@ -5,11 +5,9 @@
 
 namespace vcpkg
 {
-    const char* PackageSpecParseResultCategoryImpl::name() const noexcept { return "PackageSpecParseResult"; }
-
-    std::string PackageSpecParseResultCategoryImpl::message(int ev) const noexcept
+    CStringView to_string(PackageSpecParseResult ev) noexcept
     {
-        switch (static_cast<PackageSpecParseResult>(ev))
+        switch (ev)
         {
             case PackageSpecParseResult::SUCCESS: return "OK";
             case PackageSpecParseResult::TOO_MANY_COLONS: return "Too many colons";
@@ -19,22 +17,4 @@ namespace vcpkg
             default: Checks::unreachable(VCPKG_LINE_INFO);
         }
     }
-
-    const std::error_category& package_spec_parse_result_category()
-    {
-        static PackageSpecParseResultCategoryImpl instance;
-        return instance;
-    }
-
-    std::error_code make_error_code(PackageSpecParseResult e)
-    {
-        return std::error_code(static_cast<int>(e), package_spec_parse_result_category());
-    }
-
-    PackageSpecParseResult to_package_spec_parse_result(int i) { return static_cast<PackageSpecParseResult>(i); }
-
-    PackageSpecParseResult to_package_spec_parse_result(std::error_code ec)
-    {
-        return to_package_spec_parse_result(ec.value());
-    }
 }
diff --git a/toolsrc/src/Paragraphs.cpp b/toolsrc/src/Paragraphs.cpp
index 70d3db2b3..13103d1f8 100644
--- a/toolsrc/src/Paragraphs.cpp
+++ b/toolsrc/src/Paragraphs.cpp
@@ -168,7 +168,7 @@ namespace vcpkg::Paragraphs
             return parse_single_paragraph(*spgh);
         }
 
-        return contents.error_code();
+        return contents.error();
     }
 
     Expected<std::vector<std::unordered_map<std::string, std::string>>> get_paragraphs(const Files::Filesystem& fs,
@@ -180,7 +180,7 @@ namespace vcpkg::Paragraphs
             return parse_paragraphs(*spgh);
         }
 
-        return contents.error_code();
+        return contents.error();
     }
 
     Expected<std::unordered_map<std::string, std::string>> parse_single_paragraph(const std::string& str)
@@ -201,15 +201,16 @@ namespace vcpkg::Paragraphs
         return Parser(str.c_str(), str.c_str() + str.size()).get_paragraphs();
     }
 
-    Expected<SourceParagraph> try_load_port(const Files::Filesystem& fs, const fs::path& path)
+    ExpectedT<SourceParagraph, ParseControlErrorInfo> try_load_port(const Files::Filesystem& fs, const fs::path& path)
     {
+        ParseControlErrorInfo error_info;
         Expected<std::unordered_map<std::string, std::string>> pghs = get_single_paragraph(fs, path / "CONTROL");
         if (auto p = pghs.get())
         {
-            return SourceParagraph(*p);
+            return SourceParagraph::parse_control_file(*p);
         }
-
-        return pghs.error_code();
+        error_info.error = pghs.error();
+        return error_info;
     }
 
     Expected<BinaryParagraph> try_load_cached_package(const VcpkgPaths& paths, const PackageSpec& spec)
@@ -222,20 +223,26 @@ namespace vcpkg::Paragraphs
             return BinaryParagraph(*p);
         }
 
-        return pghs.error_code();
+        return pghs.error();
     }
 
     std::vector<SourceParagraph> load_all_ports(const Files::Filesystem& fs, const fs::path& ports_dir)
     {
         std::vector<SourceParagraph> output;
+        std::vector<ParseControlErrorInfo> port_errors;
         for (auto&& path : fs.get_files_non_recursive(ports_dir))
         {
-            Expected<SourceParagraph> source_paragraph = try_load_port(fs, path);
+            ExpectedT<SourceParagraph, ParseControlErrorInfo> source_paragraph = try_load_port(fs, path);
             if (auto srcpgh = source_paragraph.get())
             {
                 output.emplace_back(std::move(*srcpgh));
             }
+            else
+            {
+                port_errors.emplace_back(source_paragraph.error());
+            }
         }
+        print_error_message(port_errors);
 
         return output;
     }
diff --git a/toolsrc/src/SourceParagraph.cpp b/toolsrc/src/SourceParagraph.cpp
index d140ce72b..9516681c9 100644
--- a/toolsrc/src/SourceParagraph.cpp
+++ b/toolsrc/src/SourceParagraph.cpp
@@ -5,6 +5,8 @@
 #include "vcpkg_Checks.h"
 #include "vcpkg_Maps.h"
 #include "vcpkg_System.h"
+#include "vcpkg_expected.h"
+
 #include "vcpkglib_helpers.h"
 
 namespace vcpkg
@@ -37,15 +39,41 @@ namespace vcpkg
 
     SourceParagraph::SourceParagraph() = default;
 
-    SourceParagraph::SourceParagraph(std::unordered_map<std::string, std::string> fields)
+    void print_error_message(const ParseControlErrorInfo& info)
+    {
+        System::println(
+            System::Color::error, "Error: There are invalid fields in the Source Paragraph of %s", info.name);
+        System::println("The following fields were not expected:\n\n    %s\n\n", info.remaining_fields_as_string);
+        System::println("This is the list of valid fields (case-sensitive): \n\n    %s\n", info.valid_fields_as_string);
+        System::println("Different source may be available for vcpkg. Use .\\bootstrap-vcpkg.bat to update.\n");
+    }
+
+    void print_error_message(std::vector<ParseControlErrorInfo> error_info_list)
+    {
+        for (ParseControlErrorInfo error_info : error_info_list)
+        {
+            System::println(
+                System::Color::error, "Error: There are invalid fields in the Source Paragraph of %s", error_info.name);
+            System::println("The following fields were not expected:\n\n    %s\n\n",
+                            error_info.remaining_fields_as_string);
+        }
+
+        System::println("This is the list of valid fields (case-sensitive): \n\n    %s\n",
+                        error_info_list.front().valid_fields_as_string);
+        System::println("Different source may be available for vcpkg. Use .\\bootstrap-vcpkg.bat to update.\n");
+    }
+
+    ExpectedT<SourceParagraph, ParseControlErrorInfo> SourceParagraph::parse_control_file(
+        std::unordered_map<std::string, std::string> fields)
     {
-        this->name = details::remove_required_field(&fields, SourceParagraphRequiredField::SOURCE);
-        this->version = details::remove_required_field(&fields, SourceParagraphRequiredField::VERSION);
-        this->description = details::remove_optional_field(&fields, SourceParagraphOptionalField::DESCRIPTION);
-        this->maintainer = details::remove_optional_field(&fields, SourceParagraphOptionalField::MAINTAINER);
+        SourceParagraph sparagraph;
+        sparagraph.name = details::remove_required_field(&fields, SourceParagraphRequiredField::SOURCE);
+        sparagraph.version = details::remove_required_field(&fields, SourceParagraphRequiredField::VERSION);
+        sparagraph.description = details::remove_optional_field(&fields, SourceParagraphOptionalField::DESCRIPTION);
+        sparagraph.maintainer = details::remove_optional_field(&fields, SourceParagraphOptionalField::MAINTAINER);
 
         std::string deps = details::remove_optional_field(&fields, SourceParagraphOptionalField::BUILD_DEPENDS);
-        this->depends = expand_qualified_dependencies(parse_depends(deps));
+        sparagraph.depends = expand_qualified_dependencies(parse_depends(deps));
 
         if (!fields.empty())
         {
@@ -55,12 +83,9 @@ namespace vcpkg
             const std::string remaining_fields_as_string = Strings::join("\n    ", remaining_fields);
             const std::string valid_fields_as_string = Strings::join("\n    ", valid_fields);
 
-            System::println(
-                System::Color::error, "Error: There are invalid fields in the Source Paragraph of %s", this->name);
-            System::println("The following fields were not expected:\n\n    %s\n\n", remaining_fields_as_string);
-            System::println("This is the list of valid fields (case-sensitive): \n\n    %s\n", valid_fields_as_string);
-            Checks::exit_fail(VCPKG_LINE_INFO);
+            return ParseControlErrorInfo{sparagraph.name, remaining_fields_as_string, valid_fields_as_string};
         }
+        return sparagraph;
     }
 
     std::vector<Dependency> vcpkg::expand_qualified_dependencies(const std::vector<std::string>& depends)
diff --git a/toolsrc/src/commands_build.cpp b/toolsrc/src/commands_build.cpp
index ec6586fa3..4a0cee021 100644
--- a/toolsrc/src/commands_build.cpp
+++ b/toolsrc/src/commands_build.cpp
@@ -33,13 +33,16 @@ namespace vcpkg::Commands::BuildCommand
             Checks::exit_success(VCPKG_LINE_INFO);
         }
 
-        const Expected<SourceParagraph> maybe_spgh = Paragraphs::try_load_port(paths.get_filesystem(), port_dir);
-        Checks::check_exit(VCPKG_LINE_INFO,
-                           !maybe_spgh.error_code(),
-                           "Could not find package %s: %s",
-                           spec,
-                           maybe_spgh.error_code().message());
-        const SourceParagraph& spgh = *maybe_spgh.get();
+        const ExpectedT<SourceParagraph, ParseControlErrorInfo> maybe_spgh =
+            Paragraphs::try_load_port(paths.get_filesystem(), port_dir);
+        // why do we add a const here
+        if (!maybe_spgh)
+        {
+            print_error_message(maybe_spgh.error());
+            Checks::exit_fail(VCPKG_LINE_INFO);
+        }
+
+        const SourceParagraph& spgh = maybe_spgh.value_or_exit(VCPKG_LINE_INFO);
         Checks::check_exit(VCPKG_LINE_INFO,
                            spec.name() == spgh.name,
                            "The Name: field inside the CONTROL does not match the port directory: '%s' != '%s'",
diff --git a/toolsrc/src/tests_paragraph.cpp b/toolsrc/src/tests_paragraph.cpp
index b66adc816..1c77b437b 100644
--- a/toolsrc/src/tests_paragraph.cpp
+++ b/toolsrc/src/tests_paragraph.cpp
@@ -25,7 +25,10 @@ namespace UnitTest1
     {
         TEST_METHOD(SourceParagraph_Construct_Minimum)
         {
-            vcpkg::SourceParagraph pgh({{"Source", "zlib"}, {"Version", "1.2.8"}});
+            auto m_pgh = vcpkg::SourceParagraph::parse_control_file({{"Source", "zlib"}, {"Version", "1.2.8"}});
+
+            Assert::IsTrue(m_pgh.has_value());
+            auto& pgh = *m_pgh.get();
 
             Assert::AreEqual("zlib", pgh.name.c_str());
             Assert::AreEqual("1.2.8", pgh.version.c_str());
@@ -36,11 +39,12 @@ namespace UnitTest1
 
         TEST_METHOD(SourceParagraph_Construct_Maximum)
         {
-            vcpkg::SourceParagraph pgh({{"Source", "s"},
-                                        {"Version", "v"},
-                                        {"Maintainer", "m"},
-                                        {"Description", "d"},
-                                        {"Build-Depends", "bd"}});
+            auto m_pgh = vcpkg::SourceParagraph::parse_control_file({
+                {"Source", "s"}, {"Version", "v"}, {"Maintainer", "m"}, {"Description", "d"}, {"Build-Depends", "bd"},
+            });
+            Assert::IsTrue(m_pgh.has_value());
+            auto& pgh = *m_pgh.get();
+
             Assert::AreEqual("s", pgh.name.c_str());
             Assert::AreEqual("v", pgh.version.c_str());
             Assert::AreEqual("m", pgh.maintainer.c_str());
@@ -51,7 +55,11 @@ namespace UnitTest1
 
         TEST_METHOD(SourceParagraph_Two_Depends)
         {
-            vcpkg::SourceParagraph pgh({{"Source", "zlib"}, {"Version", "1.2.8"}, {"Build-Depends", "z, openssl"}});
+            auto m_pgh = vcpkg::SourceParagraph::parse_control_file({
+                {"Source", "zlib"}, {"Version", "1.2.8"}, {"Build-Depends", "z, openssl"},
+            });
+            Assert::IsTrue(m_pgh.has_value());
+            auto& pgh = *m_pgh.get();
 
             Assert::AreEqual(size_t(2), pgh.depends.size());
             Assert::AreEqual("z", pgh.depends[0].name.c_str());
@@ -60,8 +68,11 @@ namespace UnitTest1
 
         TEST_METHOD(SourceParagraph_Three_Depends)
         {
-            vcpkg::SourceParagraph pgh(
-                {{"Source", "zlib"}, {"Version", "1.2.8"}, {"Build-Depends", "z, openssl, xyz"}});
+            auto m_pgh = vcpkg::SourceParagraph::parse_control_file({
+                {"Source", "zlib"}, {"Version", "1.2.8"}, {"Build-Depends", "z, openssl, xyz"},
+            });
+            Assert::IsTrue(m_pgh.has_value());
+            auto& pgh = *m_pgh.get();
 
             Assert::AreEqual(size_t(3), pgh.depends.size());
             Assert::AreEqual("z", pgh.depends[0].name.c_str());
@@ -71,8 +82,11 @@ namespace UnitTest1
 
         TEST_METHOD(SourceParagraph_Construct_Qualified_Depends)
         {
-            vcpkg::SourceParagraph pgh(
-                {{"Source", "zlib"}, {"Version", "1.2.8"}, {"Build-Depends", "libA [windows], libB [uwp]"}});
+            auto m_pgh = vcpkg::SourceParagraph::parse_control_file({
+                {"Source", "zlib"}, {"Version", "1.2.8"}, {"Build-Depends", "libA [windows], libB [uwp]"},
+            });
+            Assert::IsTrue(m_pgh.has_value());
+            auto& pgh = *m_pgh.get();
 
             Assert::AreEqual("zlib", pgh.name.c_str());
             Assert::AreEqual("1.2.8", pgh.version.c_str());
@@ -101,13 +115,15 @@ namespace UnitTest1
 
         TEST_METHOD(BinaryParagraph_Construct_Maximum)
         {
-            vcpkg::BinaryParagraph pgh({{"Package", "s"},
-                                        {"Version", "v"},
-                                        {"Architecture", "x86-windows"},
-                                        {"Multi-Arch", "same"},
-                                        {"Maintainer", "m"},
-                                        {"Description", "d"},
-                                        {"Depends", "bd"}});
+            vcpkg::BinaryParagraph pgh({
+                {"Package", "s"},
+                {"Version", "v"},
+                {"Architecture", "x86-windows"},
+                {"Multi-Arch", "same"},
+                {"Maintainer", "m"},
+                {"Description", "d"},
+                {"Depends", "bd"},
+            });
             Assert::AreEqual("s", pgh.spec.name().c_str());
             Assert::AreEqual("v", pgh.version.c_str());
             Assert::AreEqual("m", pgh.maintainer.c_str());
@@ -327,28 +343,26 @@ namespace UnitTest1
 
         TEST_METHOD(package_spec_parse)
         {
-            vcpkg::Expected<vcpkg::PackageSpec> spec =
+            vcpkg::ExpectedT<vcpkg::PackageSpec, vcpkg::PackageSpecParseResult> spec =
                 vcpkg::PackageSpec::from_string("zlib", vcpkg::Triplet::X86_WINDOWS);
-            Assert::AreEqual(vcpkg::PackageSpecParseResult::SUCCESS,
-                             vcpkg::to_package_spec_parse_result(spec.error_code()));
+            Assert::AreEqual(vcpkg::PackageSpecParseResult::SUCCESS, spec.error());
             Assert::AreEqual("zlib", spec.get()->name().c_str());
             Assert::AreEqual(vcpkg::Triplet::X86_WINDOWS.canonical_name(), spec.get()->triplet().canonical_name());
         }
 
         TEST_METHOD(package_spec_parse_with_arch)
         {
-            vcpkg::Expected<vcpkg::PackageSpec> spec =
+            vcpkg::ExpectedT<vcpkg::PackageSpec, vcpkg::PackageSpecParseResult> spec =
                 vcpkg::PackageSpec::from_string("zlib:x64-uwp", vcpkg::Triplet::X86_WINDOWS);
-            Assert::AreEqual(vcpkg::PackageSpecParseResult::SUCCESS,
-                             vcpkg::to_package_spec_parse_result(spec.error_code()));
+            Assert::AreEqual(vcpkg::PackageSpecParseResult::SUCCESS, spec.error());
             Assert::AreEqual("zlib", spec.get()->name().c_str());
             Assert::AreEqual(vcpkg::Triplet::X64_UWP.canonical_name(), spec.get()->triplet().canonical_name());
         }
 
         TEST_METHOD(package_spec_parse_with_multiple_colon)
         {
-            auto ec = vcpkg::PackageSpec::from_string("zlib:x86-uwp:", vcpkg::Triplet::X86_WINDOWS).error_code();
-            Assert::AreEqual(vcpkg::PackageSpecParseResult::TOO_MANY_COLONS, vcpkg::to_package_spec_parse_result(ec));
+            auto ec = vcpkg::PackageSpec::from_string("zlib:x86-uwp:", vcpkg::Triplet::X86_WINDOWS).error();
+            Assert::AreEqual(vcpkg::PackageSpecParseResult::TOO_MANY_COLONS, ec);
         }
 
         TEST_METHOD(utf8_to_utf16)
diff --git a/toolsrc/src/vcpkg.cpp b/toolsrc/src/vcpkg.cpp
index 154aefd0a..738b7b284 100644
--- a/toolsrc/src/vcpkg.cpp
+++ b/toolsrc/src/vcpkg.cpp
@@ -61,10 +61,10 @@ static void inner(const VcpkgCmdArguments& args)
 
     const Expected<VcpkgPaths> expected_paths = VcpkgPaths::create(vcpkg_root_dir);
     Checks::check_exit(VCPKG_LINE_INFO,
-                       !expected_paths.error_code(),
+                       !expected_paths.error(),
                        "Error: Invalid vcpkg root directory %s: %s",
                        vcpkg_root_dir.string(),
-                       expected_paths.error_code().message());
+                       expected_paths.error().message());
     const VcpkgPaths paths = expected_paths.value_or_exit(VCPKG_LINE_INFO);
     int exit_code = _wchdir(paths.root.c_str());
     Checks::check_exit(VCPKG_LINE_INFO, exit_code == 0, "Changing the working dir failed");
diff --git a/toolsrc/src/vcpkg_Dependencies.cpp b/toolsrc/src/vcpkg_Dependencies.cpp
index acfb55239..ea5832e46 100644
--- a/toolsrc/src/vcpkg_Dependencies.cpp
+++ b/toolsrc/src/vcpkg_Dependencies.cpp
@@ -174,11 +174,14 @@ namespace vcpkg::Dependencies
                 if (auto bpgh = maybe_bpgh.get())
                     return InstallPlanAction{spec, {nullopt, *bpgh, nullopt}, request_type};
 
-                Expected<SourceParagraph> maybe_spgh =
+                ExpectedT<SourceParagraph, ParseControlErrorInfo> maybe_spgh =
                     Paragraphs::try_load_port(paths.get_filesystem(), paths.port_dir(spec));
                 if (auto spgh = maybe_spgh.get())
                     return InstallPlanAction{spec, {nullopt, nullopt, *spgh}, request_type};
 
+                else
+                    print_error_message(maybe_spgh.error());
+
                 Checks::exit_with_message(VCPKG_LINE_INFO, "Could not find package %s", spec);
             }
         };
@@ -283,11 +286,14 @@ namespace vcpkg::Dependencies
                 if (auto bpgh = maybe_bpgh.get())
                     return ExportPlanAction{spec, {nullopt, *bpgh, nullopt}, request_type};
 
-                Expected<SourceParagraph> maybe_spgh =
+                ExpectedT<SourceParagraph, ParseControlErrorInfo> maybe_spgh =
                     Paragraphs::try_load_port(paths.get_filesystem(), paths.port_dir(spec));
                 if (auto spgh = maybe_spgh.get())
                     return ExportPlanAction{spec, {nullopt, nullopt, *spgh}, request_type};
 
+                else
+                    print_error_message(maybe_spgh.error());
+
                 Checks::exit_with_message(VCPKG_LINE_INFO, "Could not find package %s", spec);
             }
         };
diff --git a/toolsrc/src/vcpkg_Files.cpp b/toolsrc/src/vcpkg_Files.cpp
index 17aa2997a..7b12ea699 100644
--- a/toolsrc/src/vcpkg_Files.cpp
+++ b/toolsrc/src/vcpkg_Files.cpp
@@ -15,7 +15,7 @@ namespace vcpkg::Files
             std::fstream file_stream(file_path, std::ios_base::in | std::ios_base::binary);
             if (file_stream.fail())
             {
-                return std::errc::no_such_file_or_directory;
+                return std::make_error_code(std::errc::no_such_file_or_directory);
             }
 
             file_stream.seekg(0, file_stream.end);
@@ -24,7 +24,7 @@ namespace vcpkg::Files
 
             if (length > SIZE_MAX)
             {
-                return std::errc::file_too_large;
+                return std::make_error_code(std::errc::file_too_large);
             }
 
             std::string output;
@@ -39,7 +39,7 @@ namespace vcpkg::Files
             std::fstream file_stream(file_path, std::ios_base::in | std::ios_base::binary);
             if (file_stream.fail())
             {
-                return std::errc::no_such_file_or_directory;
+                return std::make_error_code(std::errc::no_such_file_or_directory);
             }
 
             std::vector<std::string> output;
diff --git a/toolsrc/src/vcpkg_Input.cpp b/toolsrc/src/vcpkg_Input.cpp
index 7d8e4767e..df738315b 100644
--- a/toolsrc/src/vcpkg_Input.cpp
+++ b/toolsrc/src/vcpkg_Input.cpp
@@ -12,14 +12,14 @@ namespace vcpkg::Input
                                            CStringView example_text)
     {
         const std::string as_lowercase = Strings::ascii_to_lowercase(package_spec_as_string);
-        Expected<PackageSpec> expected_spec = PackageSpec::from_string(as_lowercase, default_triplet);
+        auto expected_spec = PackageSpec::from_string(as_lowercase, default_triplet);
         if (auto spec = expected_spec.get())
         {
             return *spec;
         }
 
         // Intentionally show the lowercased string
-        System::println(System::Color::error, "Error: %s: %s", expected_spec.error_code().message(), as_lowercase);
+        System::println(System::Color::error, "Error: %s: %s", vcpkg::to_string(expected_spec.error()), as_lowercase);
         System::print(example_text);
         Checks::exit_fail(VCPKG_LINE_INFO);
     }