Lec 06 and 07 updates

Author: PeterTh

06_advanced_templates/06_07_dispatch.cpp

@@ -99,7 +99,7 @@ std::enable_if_t<!has_print_to_v<T>> dump(T t) {
 
 // Will work automatically for all classes matching the pattern
 
-#endif 
+#endif
 
 /// Option 3: C++17 "if constexpr" ////////////////////////////////////////////
 

06_advanced_templates/06_08_decltype_declval.cpp

@@ -22,6 +22,6 @@ int main() {
 	std::cout << sizeof(fun()) << std::endl;
 	// also allowed -- also an unevaluated context
 
-	// fun();
+	//fun();
 	// ^ this causes a linker error (used in evaluated context)
 }

06_advanced_templates/06_09_sfinae.cpp

@@ -13,7 +13,7 @@ bool is_odd(int[1][N % 2 == 0 ? 1 : -1] = nullptr) {
 
 int main() {
 
-	// int x[-1];
+	//int x[-1];
 	// ^ this is a compiler error - we can't use a negative array length
 
 	std::cout << "is_odd<0>()  : " << is_odd<0>() << std::endl;

06_advanced_templates/06_advanced_templates.vcxproj

@@ -19,7 +19,7 @@
     </ProjectConfiguration>
   </ItemGroup>
   <ItemGroup>
-    <ClCompile Include="06_06_tuple_includes_prime.cpp" />
+    <ClCompile Include="06_10_crtp.cpp" />
   </ItemGroup>
   <PropertyGroup Label="Globals">
     <VCProjectVersion>15.0</VCProjectVersion>

07_libraries/07_02_threads.cpp

@@ -5,8 +5,9 @@
 
 void replace_string_thread(std::string& target, std::mutex& target_mutex,
 		const std::string to_replace, const std::string replacement) {
-	std::lock_guard<std::mutex> lock(target_mutex);
+	std::lock_guard lock(target_mutex);
 	//             ^ in C++17 we can omit the template parameter (deduction guides)
+	//               in earlier versions we need to explicitly write "<std::mutex>"
 	// lock_guard is a *scoped lock*
 	target.replace(target.find(to_replace), to_replace.size(), replacement);
 }

07_libraries/07_03_future_fs.cpp

@@ -1,32 +1,46 @@
 #include <iostream>
 #include <string>
 #include <future>
+#include <chrono>
 
 #include <filesystem>
 namespace fs = std::filesystem;
 
-// Note: needs to be linked with -lstdc++fs (in GCC)
+// Note: needs to be linked with -lstdc++fs (in GCC 8.2)
+// experimental in earlier compilers
 
 int main() {
+	using namespace std::chrono_literals;
 
 	auto largest_future = std::async([]() {
 		// find largest file in working directory
 		decltype(fs::file_size(std::declval<fs::path>())) largest_size = 0;
 		fs::path largest;
-		for(auto& p : fs::directory_iterator(".")) {
-			auto path = p.path();
-			auto s = fs::file_size(path);
-			if(s > largest_size) {
-				largest_size = s;
-				largest = path;
+		try {
+			for(auto& p : fs::recursive_directory_iterator("R:/")) {
+				if(p.is_regular_file()) {
+					auto path = p.path();
+					auto s = fs::file_size(path);
+					if(s > largest_size) {
+						largest_size = s;
+						largest = path;
+					}
+				}
 			}
 		}
+		// when dealing with files, getting an exception isn't unlikely
+		catch(std::exception& e) {
+			std::cerr << std::endl << "Exception: " << e.what() << std::endl;
+		}
 		return largest;
 	});
 
-	std::cout << "Searching for largest file..." << std::endl;
+	std::cout << "Searching for largest file...";
 
 	// ... other work / progress bar / etc
+	while(largest_future.wait_for(250ms) != std::future_status::ready) {
+		std::cout << ".";
+	}
 
-	std::cout << "Largest file: " << largest_future.get() << std::endl;
+	std::cout << std::endl << "Largest file: " << largest_future.get().generic_string() << std::endl;
 }

07_libraries/07_libraries.vcxproj

@@ -19,7 +19,7 @@
     </ProjectConfiguration>
   </ItemGroup>
   <ItemGroup>
-    <ClCompile Include="07_10_eigen.cpp" />
+    <ClCompile Include="07_04_boost_format.cpp" />
   </ItemGroup>
   <PropertyGroup Label="Globals">
     <VCProjectVersion>15.0</VCProjectVersion>
@@ -77,12 +77,24 @@
     <RunCodeAnalysis>false</RunCodeAnalysis>
     <EnableCppCoreCheck>true</EnableCppCoreCheck>
     <IncludePath>D:\dev\eigen;$(IncludePath)</IncludePath>
+    <OutDir>$(TMP)\$(ProjectName)\$(Platform)\$(Configuration)\</OutDir>
+    <IntDir>$(TMP)\$(ProjectName)\tmp\$(Platform)\$(Configuration)\</IntDir>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
     <CodeAnalysisRuleSet>NativeRecommendedRules.ruleset</CodeAnalysisRuleSet>
     <RunCodeAnalysis>false</RunCodeAnalysis>
     <EnableCppCoreCheck>true</EnableCppCoreCheck>
     <IncludePath>D:\dev\eigen;$(IncludePath)</IncludePath>
+    <OutDir>$(TMP)\$(ProjectName)\$(Platform)\$(Configuration)\</OutDir>
+    <IntDir>$(TMP)\$(ProjectName)\tmp\$(Platform)\$(Configuration)\</IntDir>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <OutDir>$(TMP)\$(ProjectName)\$(Platform)\$(Configuration)\</OutDir>
+    <IntDir>$(TMP)\$(ProjectName)\tmp\$(Platform)\$(Configuration)\</IntDir>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
+    <OutDir>$(TMP)\$(ProjectName)\$(Platform)\$(Configuration)\</OutDir>
+    <IntDir>$(TMP)\$(ProjectName)\tmp\$(Platform)\$(Configuration)\</IntDir>
   </PropertyGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
     <ClCompile>