Function EvaluateNTTPAsConstantExpr

CodeGenerator.cpp:1767–1779

\brief Evaluates a potential NTTP as a constant expression. Used for C++20's struct/class as NTTP.

///
/// Used for C++20's struct/class as NTTP.
static std::optional<std::pair<QualType, APValue>> EvaluateNTTPAsConstantExpr(const Expr* expr)
{
    expr = expr->IgnoreParenImpCasts();

    // The marker when it is a C++20 class as NTTP seems to be CXXFunctionalCastExpr
    if(Expr::EvalResult evalResult{};
       isa<CXXFunctionalCastExpr>(expr) and
       expr->EvaluateAsConstantExpr(evalResult, GetGlobalAST(), ConstantExprKind::Normal)) {
        return std::pair<QualType, APValue>{expr->getType(), evalResult.Val};
    }

    return {};
}
//-----------------------------------------------------------------------------

void CodeGenerator::InsertTemplateParameters(const TemplateParameterList& list,