Hover
Rich information cards for the symbol under the cursor.
Symbol Information
Qualified name
The hover card shows the enclosing namespace and class scope
Symbol kind
The card names what the symbol is: struct, enum, function, field, …
Access specifier
Members show their public / protected / private access
Definition rendering
The card includes the symbol's source definition
Initializer truncation
Huge initializers render truncated, not in full
The rendered definition omits the initializer, and the evaluated Value field shows the first ten of its 256 elements.
Virtual modifiers
virtual / override / final show on method hover
Modifiers written in the source render (virtual … = 0, override, final), but an overriding method that omits the redundant virtual keyword gives no sign of its virtuality — the card lacks the virtual void draw() override form the issue asks for.
Anonymous namespace scope
(anonymous namespace) shows in the scope display
The cards render, but the anonymous segment is dropped from the scope display: a top-level anonymous member shows no scope line at all, and outer::(anonymous) shows just outer.
Type Information
Variable types
Variable hover preserves pointer, reference and array declarators
A variable's card pretty-prints its declared type, spelling the pointer, reference and array declarators the way they read in source.
Type aliases
Hover can show the desugared aka form
A sugared type shows its underlying type as Alias (aka int). The show_aka option turns the aka suffix off.
Function signatures
Function hover reports return types, parameter names and defaults
A function's card lists its return type, each parameter with its name, and any default argument.
Template parameters
Template hover distinguishes type, template-template and non-type parameters
Each template parameter kind reports its form: a type parameter, a template-template parameter, and a non-type parameter with its default.
auto deduction
Placeholder hover shows the type it resolves to
Hovering an auto placeholder shows the type substituted for it — builtins, pointers, lambdas, template instantiations, and the /* not deduced */ marker inside an uninstantiated template.
decltype deduction
Decltype hover distinguishes value, reference and dependent forms
Hovering a decltype or decltype(auto) placeholder shows the resolved type, including the reference the parenthesized-expression rule adds.
CTAD
Class placeholder hover shows its deduced template arguments
With class template argument deduction the variable's card shows the deduced Box<int>, but hovering the class-name spelling still reports the primary template without its arguments.
Instantiation arguments
Template use hover does not show parameter-to-argument bindings yet
A use of a template shows the substituted types (Wrapper<int>, identity<int>, int x), but not an explicit T = int mapping of each parameter to the argument it was bound to.
Lambda auto parameters
Generic lambda parameters do not show their deduced type yet
Hovering the auto parameter of a generic lambda yields no card; the deduced parameter type is not shown.
Sugared auto
Alias spelling survives auto deduction
Hover keeps the alias spelling and appends its desugared form, so auto deduced from an aliased return type reads as Outer // aka: int.
Type formatting
Long and nested rendered types are not rewrapped or aligned
Long or nested types are not rewrapped or aligned.
Anonymous struct typedef
C typedef hover names an anonymous struct after its alias
Both the alias and a variable of it report a clean Point card rather than presenting the anonymous type as a separately named struct.
Concept constraints
Constrained placeholders lose their constraint on hover
The constrained-parameter and concept-reference cards carry the constraint, but hovering the placeholder of a constrained Addable auto variable shows only the deduced type — the constraint is dropped.
Layout Information
Field layout
Size, offset, alignment and padding show on field hover
Type-level layout
Hovering the type itself shows its size, alignment and padding
Size and alignment show on the type card today; the total padding does not yet.
Vtable offset
Virtual methods show their table slot
The method card renders without any vtable fact today.
Expression Context
Constant evaluation
Constant-expression hover reports evaluated values
When an initializer is a constant expression, the card evaluates it and shows the resulting value.
Call arguments
Argument hover identifies its bound parameter
Hovering an argument at a call site shows the parameter it is passed to, naming the parameter it binds.
Pass semantics
Argument hover distinguishes value and reference passing
The argument card states how the value reaches the callee: copied by value, or bound to a mutable or const reference parameter.
Implicit conversions
Argument hover reports the target type of an implicit conversion
When an argument reaches a parameter through an implicit conversion, the card notes the target type, for both built-in and user-defined conversions.
String literals
String-literal hover reports its size in bytes
A string-literal card reports the array type and its size in bytes (const char[6], Size: 6 bytes — the length plus the null terminator), not an explicit character count.
Numeric literals
Numeric literals have no type or value hover yet
Hovering a numeric literal yields no card, unlike character and string literals, whose type and value are shown.
Record variables
Record hover can show a misleading enclosing constant value
Hovering a record-typed argument of a constant-evaluable call currently reports that call's value (Value = 7) on the variable — a value that is not the record's own.
Documentation
Doxygen /// comments
Declaration documentation appears on hover
Applies to plain functions, primary templates and their specializations; a reference resolves to the most specialized declaration's comment.
Synthesized accessor docs
Trivial getters/setters get a generated one-line description
A trivial getter or setter with no comment of its own gets a synthesized "Trivial accessor/setter for field." line in its hover card.
@copydoc tags
Copied documentation is not resolved onto the receiving symbol yet
A @copydoc target tag remains literal instead of copying target's documentation into this symbol's hover card.
Inherited override docs
An override with no comment does not inherit the base method's documentation yet
An overriding method with no comment of its own has no description on its hover card.
Overload doc sharing
A later overload does not reuse the first overload's documentation yet
Consecutive overloads often document only the first; a later undocumented overload has no description on its hover card.
Inherited constructor docs
Inherited constructors have no documentation hover yet
The name in a using Base::Base; declaration resolves to the class rather than an inherited constructor, so the base constructor's documentation has no hover surface.
Banner comments
A separated section banner still attaches to the following declaration
A // ==== Section ==== banner followed by a blank line is misattributed as documentation for the declaration below it, so the banner text appears in the card.
Declaration vs definition comments
The declaration's doc wins over a definition-site comment
The declaration's /// documentation appears at both the declaration and definition sites instead of the definition's plain // note.
Whitespace and newlines
Markdown tables in comments lose their line breaks on hover
A markdown table written across several /// lines is flattened onto one line, so the table does not render.
Comment indentation
Indented documentation blocks lose their leading indentation on hover
A doc comment whose body contains an indented block loses the block's offset, and its blank line collapses.
Template keyword from a macro
Documentation on a macro-produced template is missing from hover
When the template keyword is produced by a macro expansion, the declaration's doc comment does not appear on hover, and the card carries no description.
Comment suppression option
Misattributed documentation cannot be suppressed by configuration yet
A stray comment such as a section banner separated from the code by a blank line always reaches the hover card, and no option suppresses it.
Macro Hover
Definition text at every site
#define, use, #ifdef, defined and #undef all show the macro's definition
A macro's hover card carries its #define text wherever the name appears: the definition itself, a use, an #ifdef guard, a defined test and an #undef.
Fully-expanded preview
A function-like macro use shows its arguments substituted through the body
Hovering a function-like macro invocation shows the #define text and a preview of the fully-expanded result with the call's arguments spliced in.
Command-line macros
-D definitions hover with a synthesized #define
A macro defined on the command line (-DFROM_CLI=7) shows a synthesized #define FROM_CLI 7 in its hover card, then its expansion.
Nested macro in arguments
A nested macro argument shows its definition without an expansion preview
The expansion preview starts at the outer invocation, so hovering an inner macro named inside the arguments shows only its definition, not an expansion preview.
Use before definition
A macro use before its definition has no hover yet
A macro name used in an #if above its own #define has no hover, while a use after the definition works normally.
#define inside the preamble
A leading macro definition has no hover card
A #define in the leading run of directives before the first declaration has no hover card, while definitions after a declaration do.
Special Hover Targets
Members on type hover
Hovering an enum or struct type lists its members
The card names the type (and a struct's layout), but the member list is not expanded — the body renders as {}.
Typedef underlying struct
Hovering an alias expands the aliased definition
The card resolves the alias to its underlying type name, but does not expand that struct's definition or member list.
Keyword documentation
Language keywords do not have documentation hover yet
Hovering a keyword such as const or virtual produces no card.
Attribute documentation
Hovering an attribute shows its description
The attribute's own documentation renders in the card, for both GNU __attribute__ spellings and C++ [[...]] attributes.
Include directive hover
Hovering an #include shows the resolved header path
The card resolves the quoted header to its file on disk.
this expression
Hovering this shows the pointed-to class type
Works in a plain class and inside a class template.
Predefined identifiers
__func__ hover shows the current function name
The value resolves in a concrete function; inside a template only the approximate type is known.
No hover on meaningless tokens
Builtin keywords and empty bodies yield no card
Hovering a builtin type keyword or the inside of an empty body produces no card at all, so editors show nothing rather than noise. (Numeric and bool literals also have no card today, but that is a tracked gap — see the numeric-literal item — not a promise.)
GTK-Doc and kernel-doc
GObject Introspection annotations do not appear in hover cards yet
GTK-Doc / kernel-doc comment syntax and GObject Introspection annotations are not parsed into the hover card.
LaTeX math in Doxygen
Inline Doxygen formulas are not rendered as math
The formula text is not rendered as math.
Presentation
Markdown rendering
Cards render as markdown, or plain text via parse_comment_as_markdown = false
Module-Related
Import statement hover
Hovering import does not describe the imported module yet
Hovering an import declaration does not yet describe the imported module.
Module name hover
Hovering a module name shows the interface unit that defines it
The card names the module and the file of its interface unit, on the name in an import and in the module declaration alike.
Export status hover
The card of a module's declaration shows whether the module exports it
An exported declaration's definition reads export, whether exported on its own or in an export block; a declaration the module keeps to itself, or a member of an exported class, does not.
Hover Correctness
Robustness on inputs that have broken other tooling.
MSVC inheritance model
MSVC inheritance model attributes do not alter record hover
Under an MSVC target, the implicit inheritance attribute does not leak into the record or method card.
Most-vexing-parse
Direct initialization and a function declaration have distinct hover cards
The direct initialization appears as a variable, while the most-vexing form appears as a function declaration.
Large unsigned enum constant
Hovering a 0xFFFF...ULL enumerator does not crash
The card renders the full unsigned value without overflowing or failing.
Call with default arguments
Hovering a call that omits defaults does not crash
The call card renders the callee signature with its default arguments.
Macro-shadowed symbol
A function-like macro shadows a same-named function at the call site
The card shows the active macro and its expansion instead of the shadowed function.