Warnings

Overview

Generates compiler-specific preprocessor directives that emit warnings when compiled. Integrates code generator diagnostics into the build process.

Why Use This?

Generated code may have issues detectable only at generation time (incomplete type support, deprecated patterns). compile_warnings lets generators inject warnings into output files so users see diagnostics when compiling, not when running the generator.

Types

Type	Description
compile_warnings	Warning accumulator that generates preprocessor directives
compile_warnings::entry	Single warning with message and optional location

compile_warnings::entry Fields

Field	Type	Description
message	std::string	Warning text
loc	source_location	Optional file:line context

Functions

compile_warnings()

Default constructor.

push

Add a warning.

Signature: compile_warnings& push(const std::string& message, source_location loc = {})

Parameters:

• message — warning text
• loc — optional source location for context

Returns: *this for chaining

build

Generate preprocessor directive strings for all accumulated warnings.

Signature: std::string build() const

Returns: string containing #pragma message (MSVC) and #warning (GCC/Clang) directives

get_warnings

Access the raw warning list.

Signature: const std::vector<entry>& get_warnings() const

Notes:

• Warnings appear when the generated file is compiled, not when the generator runs.
• No deduplication: the same warning can be pushed multiple times.
• Usually accessed through generator::warn() rather than used directly.

Example:

// Standalone usage
xccmeta::compile_warnings warnings;
warnings.push("Raw pointers require manual serialization", field->get_location());
std::string code = warnings.build();

// Through generator (preferred)
xccmeta::generator gen("output.hpp");
gen.warn("Template types not fully supported", node);