ReSharper C++ 2026.3: Class Layout, Format String Analysis, And More

JetBrains released ReSharper C++ 2026.3, adding a Class Layout tool window that visualizes the memory layout of classes, structs, and unions, including field offsets and sizes, bit-fields, base class subobjects, virtual table pointers, and padding. The release extends format string analysis beyond printf-style calls to std::format, std::print, and the {fmt} library, flagging invalid replacement fields, missing and unused arguments, and format specifications that mismatch argument types. ReSharper C++ 2026.3 also updates the Change Signature refactoring to support constructors and adds a Place in option and Make constexpr option to Extract Method, plus new CUDA inspections.

ReSharper C++ The Visual Studio Extension for C++ Development .NET Tools https://blog.jetbrains.com/rscpp/category/net-tools/ News https://blog.jetbrains.com/rscpp/category/news/ Releases https://blog.jetbrains.com/rscpp/category/releases/ Resharper C++ https://blog.jetbrains.com/rscpp/category/resharpercplusplus/ ReSharper C++ 2026.3: Class Layout, Format String Analysis, And More ReSharper C++ 2026.3 is here, with a new Class Layout tool window that visualizes the memory layout of your classes and helps you spot wasted space.. This release also improves format string analysis to cover std::format , std::print , and the {fmt} library. Other highlights include updates to the Change Signature and Extract Method refactorings, as well as new CUDA inspections. Class layout How a class is laid out in memory determines how much space each object takes, how well its data fits into CPU cache lines, and whether it matches a binary format or an ABI shared with other code. To satisfy alignment requirements, the compiler silently inserts padding between fields. As a result, a class can end up noticeably larger than the sum of its members. This can add up quickly for objects allocated in large numbers or processed in tight loops. The new Class Layout tool window visualizes the memory layout of a class, struct, or union, including the offset and size of every field and bit-field, base class subobjects, virtual table pointers, and the padding between them. This makes it easy to find padding you can eliminate, check the effect of alignas or pragma pack , and understand the layout of classes in a complex hierarchy. To open the tool window, place the caret on a class name or any reference to a class type, then choose ReSharper | Inspect | Class Layout . Alternatively, select the Class Layout item in the Alt+Enter menu. Refactorings Change Signature for constructors The Change Signature refactoring now works on constructors. You can add, remove, reorder, and change the types of constructor parameters, and ReSharper C++ updates the constructor calls throughout your code, including direct and braced initialization, new expressions, member and base class initializers, and factory functions such as std::make unique . The Change Signature dialog also has two new options that let you add or remove the static specifier on functions and the explicit specifier on constructors. Note: Some constructor calls, such as implicit conversions or calls through a custom factory template, can’t be found and therefore aren’t updated. Extract Method placement The Extract Method refactoring now has a Place in option that controls where the extracted function is placed: either next to the current function, as a free function in the namespace containing the current class, or as a free function in an anonymous namespace. A new Make constexpr option also lets you mark the extracted function constexpr . Introduce Using Directive The new Introduce Using Directive refactoring replaces namespace qualifiers, such as std in std::cout , with a using namespace directive. Format string analysis std::format , std::print , and {fmt} ReSharper C++ has long analyzed calls to printf -like functions. In 2026.3, the same analysis extends to the C++20 <format and C++23 <print standard library headers, as well as the popular {fmt} https://fmt.dev/ library. ReSharper C++ now analyzes calls to format , format to , format to n , formatted size , print , and println from both the std and fmt namespaces: - Replacement fields in the format string are highlighted. When the caret is on a replacement field, the corresponding argument is highlighted too, and vice versa. - ReSharper C++ reports invalid replacement fields, missing and unused arguments, and format strings that mix automatic and manual argument indexing. - The format specification is checked against the argument type. For example, formatting a double with the d presentation type is reported, and a quick-fix replaces it with a matching one. - Named arguments are supported for the {fmt} library via fmt::arg . printf updates The analysis of printf -like functions now supports the new format specifiers from C23. ReSharper C++ also understands POSIX positional arguments such as %1$s and %2$ 1$d , and checks the argument types by position. A new inspection reports printf calls that mix positional and non-positional arguments. Unreal Engine logging macros Format string analysis now supports UE LOGFMT and related Unreal Engine structured logging macros. ReSharper C++ highlights the fields in the format string, matches them with the arguments, and reports missing or unused arguments and invalid field names. Format attributes on constructors The jetbrains::format and gnu::format attributes can now be applied to constructors, so ReSharper C++ checks the format string in constructor calls. Additionally, ReSharper C++ now recognizes the underscore spelling of the attribute, gnu :: format printf , 1, 2 , as well as constant expressions in the attribute’s argument indices. Code analysis Clang-Tidy integration The bundled Clang-Tidy binary has been updated to LLVM 23, bringing new checks https://releases.llvm.org/23.1.0/tools/clang/tools/extra/docs/ReleaseNotes.html new-checks and improvements from the latest LLVM release. Clang-Format has been updated as well. NOLINT comments with globs in check names, such as // NOLINT readability- , now also suppress the ReSharper C++ inspections that correspond to the matching Clang-Tidy checks. Moreover, a new Additional clang-tidy command-line arguments setting on the Clang-Tidy options page lets you pass extra arguments to Clang-Tidy. Explanations for failed constraints When a requires expression evaluates to false , ReSharper C++ now shows which requirement fails and why its expression is ill-formed. For example, a function or operator may be inaccessible or deleted, or the number of arguments may not match the candidate functions. Similarly, error messages about deleted constructors and failed destructibility checks now show the full chain of reasons, down to the specific base class or field that causes the problem. CUDA ReSharper C++ 2026.3 extends its CUDA support with a new set of inspections, which you can configure in the new CUDA group on the inspection severity settings page: - Execution spaces : ReSharper C++ checks that a function can be called from the CUDA execution space of the calling code, following the rules of the CUDA Programming Guide. The check takes into account CUDA ARCH guards, CUDA runtime API functions, C library functions available in device code such as printf and malloc , and calls to overloaded operators. - Memory spaces : New inspections detect invalid uses of the device , constant , shared , managed , and grid constant specifiers. Examples include memory space specifiers on data members or function parameters, initializers on shared variables, and conflicting specifiers. - CUDA Tile : New inspections enforce the restrictions of the CUDA Tile programming model. For example, they report goto and return statements inside loops in tile global functions, as well as tile kernels launched with a block size other than 1 . A suggestion also detects loops that can be replaced with a range-based for over cuda::tiles::irange . Language support ReSharper C++ 2026.3 supports more features from recent C++ standards: - C++23 delimited escape sequences: \x{...} , \o{...} , and \u{...} P2290 https://wg21.link/p2290 . - C++26 user-generated static assert messages P2741 https://wg21.link/p2741 . - C++26 offset parameter of the embed directive P3540 https://wg21.link/p3540 . - C++26 line directives before module declarations P3868 https://wg21.link/p3868 . Visual Studio integration Out-of-Process mode In ReSharper 2026.2, Out-of-Process OOP mode became the default. It moves heavy analysis work out of the Visual Studio process, helping prevent UI freezes and keep typing smooth. In this release, we continue to polish OOP mode and fix some of the remaining issues: - Includes Analyzer is now available in OOP mode. - Visual Studio’s F8 and Shift+F8 shortcuts navigate between ReSharper’s Find Usages results. - The New from Template command is once again available in the Solution Explorer context menu for C++ projects. Unit testing in CMake projects CMake projects opened in Visual Studio’s Open Folder mode are now built before unit tests are run, according to the Build Policy setting of the unit test session. Tell us your thoughts This post covered the highlights of improvements in C++ support. Take a look at the What’s New in ReSharper 2026.3 https://entry.i18n.w3jbcom.aws.intellij.net/resharper/whatsnew/ page to learn about all the other changes introduced in this release. Among them, ReSharper 2026.3 brings Claude and Codex into Visual Studio alongside Junie. Download the latest release and let us know how it works for your projects. Subscribe to ReSharper C++ Blog updates