ICU-21107 Specify language standard versions C11 & C++17 also for MSVC.

There were until now no versions specified at all, relying on the default (or commandline overrides) to be sufficiently recent.
2025-04-04 13:05:31 +00:00 · 2024-01-03 11:42:30 +09:00 · 2024-01-03 11:42:30 +09:00 · 078b88a11a
commit 078b88a11a
parent 214ae60d94
76 changed files with 319 additions and 19 deletions
--- a/icu4c/source/common/common.vcxproj
+++ b/icu4c/source/common/common.vcxproj
@ -34,6 +34,8 @@
      <TypeLibraryName>$(OutDir)\icuuc.tlb</TypeLibraryName>
    </Midl>
    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
      <PreprocessorDefinitions>U_ATTRIBUTE_DEPRECATED=;U_COMMON_IMPLEMENTATION;U_PLATFORM_USES_ONLY_WIN32_API=1;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <DisableLanguageExtensions>false</DisableLanguageExtensions>
      <WarningLevel>Level3</WarningLevel>
--- a/icu4c/source/common/common_uwp.vcxproj
+++ b/icu4c/source/common/common_uwp.vcxproj
@ -72,6 +72,8 @@
      <TypeLibraryName>$(OutDir)\icuuc.tlb</TypeLibraryName>
    </Midl>
    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
      <AdditionalIncludeDirectories>..\..\include;..\common;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
      <!-- U_DISABLE_RENAMING -->
      <!-- U_HIDE_DRAFT_API & U_HIDE_DEPRECATED_API -->
--- a/icu4c/source/extra/uconv/uconv.vcxproj
+++ b/icu4c/source/extra/uconv/uconv.vcxproj
@ -34,9 +34,11 @@
      <TypeLibraryName>$(OutDir)\uconv.tlb</TypeLibraryName>
    </Midl>
    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
      <WarningLevel>Level3</WarningLevel>
      <CompileAs>Default</CompileAs>
-      <DisableLanguageExtensions>true</DisableLanguageExtensions>
+      <DisableLanguageExtensions>false</DisableLanguageExtensions>
      <AdditionalIncludeDirectories>..\..\..\include;..\..\common;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
      <PreprocessorDefinitions>UCONVMSG_LINK;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <PrecompiledHeaderOutputFile>$(OutDir)\uconv.pch</PrecompiledHeaderOutputFile>
--- a/icu4c/source/i18n/i18n.vcxproj
+++ b/icu4c/source/i18n/i18n.vcxproj
@ -34,6 +34,8 @@
      <TypeLibraryName>$(OutDir)\icuin.tlb</TypeLibraryName>
    </Midl>
    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
      <PreprocessorDefinitions>U_ATTRIBUTE_DEPRECATED=;U_I18N_IMPLEMENTATION;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <DisableLanguageExtensions>false</DisableLanguageExtensions>
      <WarningLevel>Level3</WarningLevel>
--- a/icu4c/source/i18n/i18n_uwp.vcxproj
+++ b/icu4c/source/i18n/i18n_uwp.vcxproj
@ -70,6 +70,8 @@
      <SuppressStartupBanner>true</SuppressStartupBanner>
    </Midl>
    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
      <AdditionalIncludeDirectories>..\..\include;..\common;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
      <!-- U_DISABLE_RENAMING -->
      <!-- U_HIDE_DRAFT_API & U_HIDE_DEPRECATED_API -->
--- a/icu4c/source/io/io.vcxproj
+++ b/icu4c/source/io/io.vcxproj
@ -34,6 +34,8 @@
      <TypeLibraryName>$(OutDir)\icuio.tlb</TypeLibraryName>
    </Midl>
    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
      <AdditionalIncludeDirectories>..\..\include;..\common;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
      <PreprocessorDefinitions>U_IO_IMPLEMENTATION;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <DisableLanguageExtensions>false</DisableLanguageExtensions>
--- a/icu4c/source/layoutex/layoutex.vcxproj
+++ b/icu4c/source/layoutex/layoutex.vcxproj
@ -34,6 +34,8 @@
    <!-- Options that are common to *all* project configurations -->
  <ItemDefinitionGroup>
    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
      <AdditionalIncludeDirectories>..\..\include;..\common;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
      <PreprocessorDefinitions>U_LAYOUTEX_IMPLEMENTATION;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <WarningLevel>Level3</WarningLevel>
--- a/icu4c/source/samples/break/break.vcxproj
+++ b/icu4c/source/samples/break/break.vcxproj
@ -33,6 +33,8 @@
  <!-- Options that are common to *all* project configurations -->
  <ItemDefinitionGroup>
    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
      <AdditionalIncludeDirectories>..\..\..\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
      <WarningLevel>Level3</WarningLevel>
    </ClCompile>
--- a/icu4c/source/samples/cal/cal.vcxproj
+++ b/icu4c/source/samples/cal/cal.vcxproj
@ -33,6 +33,8 @@
  <!-- Options that are common to *all* project configurations -->
  <ItemDefinitionGroup>
    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
      <AdditionalIncludeDirectories>..\..\..\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
      <WarningLevel>Level3</WarningLevel>
      <DisableLanguageExtensions>false</DisableLanguageExtensions>
--- a/icu4c/source/samples/case/case.vcxproj
+++ b/icu4c/source/samples/case/case.vcxproj
@ -33,9 +33,11 @@
  <!-- Options that are common to *all* project configurations -->
  <ItemDefinitionGroup>
    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
      <AdditionalIncludeDirectories>..\..\..\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
      <WarningLevel>Level3</WarningLevel>
-      <DisableLanguageExtensions>true</DisableLanguageExtensions>
+      <DisableLanguageExtensions>false</DisableLanguageExtensions>
    </ClCompile>
  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
--- a/icu4c/source/samples/citer/citer.vcxproj
+++ b/icu4c/source/samples/citer/citer.vcxproj
@ -30,6 +30,12 @@
    <IntDir Condition="'$(Configuration)|$(Platform)'=='Release|x64'">.\x64\Release\</IntDir>
    <LinkIncremental Condition="'$(Configuration)|$(Platform)'=='Release|x64'">false</LinkIncremental>
  </PropertyGroup>
+  <ItemDefinitionGroup>
+    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
+    </ClCompile>
+  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <ClCompile>
      <AdditionalIncludeDirectories>..\..\..\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
--- a/icu4c/source/samples/coll/coll.vcxproj
+++ b/icu4c/source/samples/coll/coll.vcxproj
@ -30,6 +30,12 @@
    <IntDir Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">.\x64\Debug\</IntDir>
    <LinkIncremental Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</LinkIncremental>
  </PropertyGroup>
+  <ItemDefinitionGroup>
+    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
+    </ClCompile>
+  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
    <Midl>
      <TypeLibraryName>.\x86\Release/coll.tlb</TypeLibraryName>
--- a/icu4c/source/samples/csdet/csdet.vcxproj
+++ b/icu4c/source/samples/csdet/csdet.vcxproj
@ -31,6 +31,12 @@
    <IntDir Condition="'$(Configuration)|$(Platform)'=='Release|x64'">.\x64\Release\</IntDir>
    <LinkIncremental Condition="'$(Configuration)|$(Platform)'=='Release|x64'">false</LinkIncremental>
  </PropertyGroup>
+  <ItemDefinitionGroup>
+    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
+    </ClCompile>
+  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <ClCompile>
      <AdditionalIncludeDirectories>../../../include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
--- a/icu4c/source/samples/date/date.vcxproj
+++ b/icu4c/source/samples/date/date.vcxproj
@ -30,6 +30,12 @@
    <IntDir Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">.\x64\Debug\</IntDir>
    <LinkIncremental Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</LinkIncremental>
  </PropertyGroup>
+  <ItemDefinitionGroup>
+    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
+    </ClCompile>
+  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
    <Midl>
      <TypeLibraryName>.\x86\Release/date.tlb</TypeLibraryName>
--- a/icu4c/source/samples/datefmt/datefmt.vcxproj
+++ b/icu4c/source/samples/datefmt/datefmt.vcxproj
@ -30,6 +30,12 @@
    <IntDir Condition="'$(Configuration)|$(Platform)'=='Release|x64'">.\x64\Release\</IntDir>
    <LinkIncremental Condition="'$(Configuration)|$(Platform)'=='Release|x64'">false</LinkIncremental>
  </PropertyGroup>
+  <ItemDefinitionGroup>
+    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
+    </ClCompile>
+  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <Midl>
      <TypeLibraryName>.\x86\Debug/datefmt.tlb</TypeLibraryName>
--- a/icu4c/source/samples/dtitvfmtsample/dtitvfmtsample.vcxproj
+++ b/icu4c/source/samples/dtitvfmtsample/dtitvfmtsample.vcxproj
@ -65,6 +65,12 @@
    <IntDir>.\x64\Release\</IntDir>
    <TargetName>$(ProjectName)</TargetName>
  </PropertyGroup>
+  <ItemDefinitionGroup>
+    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
+    </ClCompile>
+  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <ClCompile>
      <WarningLevel>Level3</WarningLevel>
--- a/icu4c/source/samples/dtptngsample/dtptngsample.vcxproj
+++ b/icu4c/source/samples/dtptngsample/dtptngsample.vcxproj
@ -65,6 +65,12 @@
    <IntDir>.\x64\Release\</IntDir>
    <TargetName>$(ProjectName)</TargetName>
  </PropertyGroup>
+  <ItemDefinitionGroup>
+    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
+    </ClCompile>
+  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <ClCompile>
      <WarningLevel>Level3</WarningLevel>
--- a/icu4c/source/samples/layout/layout.vcxproj
+++ b/icu4c/source/samples/layout/layout.vcxproj
@ -30,6 +30,12 @@
    <IntDir Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">.\x64\Debug\</IntDir>
    <LinkIncremental Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</LinkIncremental>
  </PropertyGroup>
+  <ItemDefinitionGroup>
+    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
+    </ClCompile>
+  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
    <Midl>
      <TypeLibraryName>.\x86\Release/layout.tlb</TypeLibraryName>
--- a/icu4c/source/samples/legacy/legacy.vcxproj
+++ b/icu4c/source/samples/legacy/legacy.vcxproj
@ -66,6 +66,12 @@
    <IntDir Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">.\x64\Debug\</IntDir>
    <LinkIncremental Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</LinkIncremental>
  </PropertyGroup>
+  <ItemDefinitionGroup>
+    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
+    </ClCompile>
+  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
    <Midl>
      <TypeLibraryName>.\x86\Release/legacy.tlb</TypeLibraryName>
--- a/icu4c/source/samples/msgfmt/msgfmt.vcxproj
+++ b/icu4c/source/samples/msgfmt/msgfmt.vcxproj
@ -30,6 +30,12 @@
    <IntDir Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">.\x64\Debug\</IntDir>
    <LinkIncremental Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</LinkIncremental>
  </PropertyGroup>
+  <ItemDefinitionGroup>
+    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
+    </ClCompile>
+  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
    <Midl>
      <TypeLibraryName>.\x86\Release/msgfmt.tlb</TypeLibraryName>
--- a/icu4c/source/samples/numfmt/numfmt.vcxproj
+++ b/icu4c/source/samples/numfmt/numfmt.vcxproj
@ -30,6 +30,12 @@
    <IntDir Condition="'$(Configuration)|$(Platform)'=='Release|x64'">.\x64\Release\</IntDir>
    <LinkIncremental Condition="'$(Configuration)|$(Platform)'=='Release|x64'">false</LinkIncremental>
  </PropertyGroup>
+  <ItemDefinitionGroup>
+    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
+    </ClCompile>
+  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <Midl>
      <TypeLibraryName>.\x86\Debug/numfmt.tlb</TypeLibraryName>
--- a/icu4c/source/samples/plurfmtsample/plurfmtsample.vcxproj
+++ b/icu4c/source/samples/plurfmtsample/plurfmtsample.vcxproj
@ -64,6 +64,12 @@
    <IntDir>.\x64\Release\</IntDir>
    <TargetName>$(ProjectName)</TargetName>
  </PropertyGroup>
+  <ItemDefinitionGroup>
+    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
+    </ClCompile>
+  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <ClCompile>
      <WarningLevel>Level3</WarningLevel>
--- a/icu4c/source/samples/props/props.vcxproj
+++ b/icu4c/source/samples/props/props.vcxproj
@ -30,6 +30,12 @@
    <IntDir Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">.\x64\Debug\</IntDir>
    <LinkIncremental Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</LinkIncremental>
  </PropertyGroup>
+  <ItemDefinitionGroup>
+    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
+    </ClCompile>
+  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
    <Midl>
      <TypeLibraryName>.\x86\Release/props.tlb</TypeLibraryName>
--- a/icu4c/source/samples/strsrch/strsrch.vcxproj
+++ b/icu4c/source/samples/strsrch/strsrch.vcxproj
@ -30,6 +30,12 @@
    <IntDir Condition="'$(Configuration)|$(Platform)'=='Release|x64'">.\x64\Release\</IntDir>
    <LinkIncremental Condition="'$(Configuration)|$(Platform)'=='Release|x64'">false</LinkIncremental>
  </PropertyGroup>
+  <ItemDefinitionGroup>
+    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
+    </ClCompile>
+  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <Midl>
      <TypeLibraryName>.\x86\Debug/strsrch.tlb</TypeLibraryName>
--- a/icu4c/source/samples/translit/translit.vcxproj
+++ b/icu4c/source/samples/translit/translit.vcxproj
@ -33,6 +33,8 @@
  <!-- Options that are common to *all* project configurations -->
  <ItemDefinitionGroup>
    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
      <AdditionalIncludeDirectories>..\..\..\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
      <WarningLevel>Level3</WarningLevel>
    </ClCompile>
--- a/icu4c/source/samples/uciter8/uciter8.vcxproj
+++ b/icu4c/source/samples/uciter8/uciter8.vcxproj
@ -33,6 +33,8 @@
  <!-- Options that are common to *all* project configurations -->
  <ItemDefinitionGroup>
    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
      <AdditionalIncludeDirectories>..\..\..\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
      <WarningLevel>Level3</WarningLevel>
    </ClCompile>
--- a/icu4c/source/samples/ucnv/ucnv.vcxproj
+++ b/icu4c/source/samples/ucnv/ucnv.vcxproj
@ -33,6 +33,8 @@
  <!-- Options that are common to *all* project configurations -->
  <ItemDefinitionGroup>
    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
      <AdditionalIncludeDirectories>..\..\..\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
      <WarningLevel>Level3</WarningLevel>
    </ClCompile>
--- a/icu4c/source/samples/udata/reader.vcxproj
+++ b/icu4c/source/samples/udata/reader.vcxproj
@ -35,6 +35,12 @@
    <IntDir>.\x64\Release\</IntDir>
    <TargetName>$(ProjectName)</TargetName>
  </PropertyGroup>
+  <ItemDefinitionGroup>
+    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
+    </ClCompile>
+  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <Midl>
      <TypeLibraryName>.\reader_Win32_Debug/reader.tlb</TypeLibraryName>
--- a/icu4c/source/samples/udata/writer.vcxproj
+++ b/icu4c/source/samples/udata/writer.vcxproj
@ -35,6 +35,12 @@
    <IntDir>.\x64\Release\</IntDir>
    <TargetName>$(ProjectName)</TargetName>
  </PropertyGroup>
+  <ItemDefinitionGroup>
+    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
+    </ClCompile>
+  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <Midl>
      <TypeLibraryName>.\x86\Debug/writer.tlb</TypeLibraryName>
--- a/icu4c/source/samples/ufortune/ufortune.vcxproj
+++ b/icu4c/source/samples/ufortune/ufortune.vcxproj
@ -32,6 +32,8 @@
      <TypeLibraryName>$(OutDir)\ufortune.tlb</TypeLibraryName>
    </Midl>
    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
      <AdditionalIncludeDirectories>..\..\..\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
      <PreprocessorDefinitions>%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <WarningLevel>Level3</WarningLevel>
--- a/icu4c/source/samples/ugrep/ugrep.vcxproj
+++ b/icu4c/source/samples/ugrep/ugrep.vcxproj
@ -26,6 +26,12 @@
    <LinkIncremental Condition="'$(Configuration)'=='Debug'">true</LinkIncremental>
    <LinkIncremental Condition="'$(Configuration)'=='Release'">false</LinkIncremental>
  </PropertyGroup>
+  <ItemDefinitionGroup>
+    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
+    </ClCompile>
+  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
    <Midl>
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--- a/icu4c/source/samples/uresb/uresb.vcxproj
+++ b/icu4c/source/samples/uresb/uresb.vcxproj
@ -33,6 +33,8 @@
  <!-- Options that are common to *all* project configurations -->
  <ItemDefinitionGroup>
    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
      <AdditionalIncludeDirectories>../../../include;../../tools/toolutil;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
      <WarningLevel>Level3</WarningLevel>
    </ClCompile>
--- a/icu4c/source/samples/ustring/ustring.vcxproj
+++ b/icu4c/source/samples/ustring/ustring.vcxproj
@ -33,6 +33,8 @@
  <!-- Options that are common to *all* project configurations -->
  <ItemDefinitionGroup>
    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
      <AdditionalIncludeDirectories>..\..\..\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
      <WarningLevel>Level3</WarningLevel>
    </ClCompile>
--- a/icu4c/source/stubdata/stubdata.vcxproj
+++ b/icu4c/source/stubdata/stubdata.vcxproj
@ -35,9 +35,11 @@
      <TypeLibraryName>$(OutDir)\icudt.tlb</TypeLibraryName>
    </Midl>
    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
      <AdditionalIncludeDirectories>..\common;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
      <PreprocessorDefinitions>STUBDATA_BUILD;%(PreprocessorDefinitions)</PreprocessorDefinitions>
-      <DisableLanguageExtensions>true</DisableLanguageExtensions>
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      <WarningLevel>Level3</WarningLevel>
      <CompileAs>Default</CompileAs>
      <PrecompiledHeaderOutputFile>$(OutDir)/icudt.pch</PrecompiledHeaderOutputFile>
--- a/icu4c/source/test/cintltst/cintltst.vcxproj
+++ b/icu4c/source/test/cintltst/cintltst.vcxproj
@ -32,6 +32,8 @@
      <TypeLibraryName>$(OutDir)\cintltst.tlb</TypeLibraryName>
    </Midl>
    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
      <WarningLevel>Level3</WarningLevel>
      <CompileAs>Default</CompileAs>
      <DisableLanguageExtensions>false</DisableLanguageExtensions>
--- a/icu4c/source/test/intltest/intltest.vcxproj
+++ b/icu4c/source/test/intltest/intltest.vcxproj
@ -33,6 +33,8 @@
      <TypeLibraryName>$(OutDir)\intltest.tlb</TypeLibraryName>
    </Midl>
    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
      <AdditionalIncludeDirectories>..\..\..\include;..\..\common;..\..\i18n;..\..\tools\toolutil;..\..\tools\ctestfw;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
      <PreprocessorDefinitions>U_ATTRIBUTE_DEPRECATED=;%(PreprocessorDefinitions)</PreprocessorDefinitions>
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--- a/icu4c/source/test/iotest/iotest.vcxproj
+++ b/icu4c/source/test/iotest/iotest.vcxproj
@ -32,9 +32,11 @@
      <TypeLibraryName>$(OutDir)\iotest.tlb</TypeLibraryName>
    </Midl>
    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
      <AdditionalIncludeDirectories>..\..\..\include;..\..\tools\ctestfw;..\..\common;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
      <PreprocessorDefinitions>U_ATTRIBUTE_DEPRECATED=;%(PreprocessorDefinitions)</PreprocessorDefinitions>
-      <DisableLanguageExtensions>true</DisableLanguageExtensions>
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      <CompileAs>Default</CompileAs>
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--- a/icu4c/source/test/letest/cletest.vcxproj
+++ b/icu4c/source/test/letest/cletest.vcxproj
@ -77,6 +77,12 @@
    <IntDir Condition="'$(Configuration)|$(Platform)'=='Release|x64'">.\x64\Release\</IntDir>
    <LinkIncremental Condition="'$(Configuration)|$(Platform)'=='Release|x64'">false</LinkIncremental>
  </PropertyGroup>
+  <ItemDefinitionGroup>
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+      <LanguageStandard>stdcpp17</LanguageStandard>
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  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <ClCompile>
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--- a/icu4c/source/test/letest/gendata.vcxproj
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@ -65,6 +65,12 @@
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-      <DisableLanguageExtensions>true</DisableLanguageExtensions>
+      <DisableLanguageExtensions>false</DisableLanguageExtensions>
      <PrecompiledHeaderOutputFile>.\x64\Release/icuswap.pch</PrecompiledHeaderOutputFile>
      <AssemblerListingLocation>.\x64\Release/</AssemblerListingLocation>
      <ObjectFileName>.\x64\Release/</ObjectFileName>
@ -190,7 +196,7 @@
      <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
      <BufferSecurityCheck>true</BufferSecurityCheck>
-      <DisableLanguageExtensions>true</DisableLanguageExtensions>
+      <DisableLanguageExtensions>false</DisableLanguageExtensions>
      <PrecompiledHeaderOutputFile>.\x64\Debug/icuswap.pch</PrecompiledHeaderOutputFile>
      <AssemblerListingLocation>.\x64\Debug/</AssemblerListingLocation>
      <ObjectFileName>.\x64\Debug/</ObjectFileName>
--- a/icu4c/source/tools/makeconv/makeconv.vcxproj
+++ b/icu4c/source/tools/makeconv/makeconv.vcxproj
@ -32,6 +32,8 @@
      <TypeLibraryName>$(OutDir)/makeconv.tlb</TypeLibraryName>
    </Midl>
    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
      <WarningLevel>Level3</WarningLevel>
      <CompileAs>Default</CompileAs>
      <DisableLanguageExtensions>false</DisableLanguageExtensions>
--- a/icu4c/source/tools/pkgdata/pkgdata.vcxproj
+++ b/icu4c/source/tools/pkgdata/pkgdata.vcxproj
@ -32,9 +32,11 @@
      <TypeLibraryName>$(OutDir)/pkgdata.tlb</TypeLibraryName>
    </Midl>
    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
      <WarningLevel>Level3</WarningLevel>
      <CompileAs>Default</CompileAs>
-      <DisableLanguageExtensions>true</DisableLanguageExtensions>
+      <DisableLanguageExtensions>false</DisableLanguageExtensions>
      <AdditionalIncludeDirectories>../../../include;../../common;../toolutil;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
      <PrecompiledHeaderOutputFile>$(OutDir)/pkgdata.pch</PrecompiledHeaderOutputFile>
      <AssemblerListingLocation>$(OutDir)/</AssemblerListingLocation>
--- a/icu4c/source/tools/toolutil/toolutil.vcxproj
+++ b/icu4c/source/tools/toolutil/toolutil.vcxproj
@ -29,7 +29,9 @@
  <!-- Options that are common to *all* project configurations -->
  <ItemDefinitionGroup>
    <ClCompile>
-       <AdditionalIncludeDirectories>..\..\..\include;..\..\common;..\..\i18n;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
+      <AdditionalIncludeDirectories>..\..\..\include;..\..\common;..\..\i18n;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
      <PreprocessorDefinitions>U_TOOLUTIL_IMPLEMENTATION;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <DisableLanguageExtensions>false</DisableLanguageExtensions>
      <WarningLevel>Level3</WarningLevel>
--- a/icu4c/source/tools/tzcode/icuzdump.vcxproj
+++ b/icu4c/source/tools/tzcode/icuzdump.vcxproj
@ -45,6 +45,12 @@
    <IntDir Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">$(Configuration)\</IntDir>
    <LinkIncremental Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">false</LinkIncremental>
  </PropertyGroup>
+  <ItemDefinitionGroup>
+    <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard_C>stdc11</LanguageStandard_C>
+    </ClCompile>
+  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <CustomBuildStep>
      <Command>copy "$(TargetPath)" ..\..\..\bin
@ -58,7 +64,7 @@
      <MinimalRebuild>false</MinimalRebuild>
      <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
-      <DisableLanguageExtensions>true</DisableLanguageExtensions>
+      <DisableLanguageExtensions>false</DisableLanguageExtensions>
      <PrecompiledHeader>
      </PrecompiledHeader>
      <PrecompiledHeaderOutputFile>.\x86\Debug/icuzdump.pch</PrecompiledHeaderOutputFile>