Template Support

[oxisto]

Just to keep track of it.

[vfsrfs]

This PR adds template support as discussed in #363

Features

• Supports Type Parameters and Value Parameters as Parameters for the TemplateDeclaration
• Supports the resolution with default parameters
• Supports use of a previously defined template parameter as a default value
• Creates dummy elements when needed
• CallExpression is extended to include an instantiation Edge to the template that is being instantiated by the call and a template parameter edge that connects the CallExpression to the parameters the template is instantiated with
• Introduces TypeExpression to model the type keywords provided when instantiating a template

ClassTemplate

• Supports templates applied to classes and structs
• Templates can be instantiated either on the stack or on the heap using the new keyword

Example:

template<class Type1, class Type2>
class Pair
{
    public:
        Type1 first;
        Type2 second;
};

int main()
{
    Pair<int,int> point1;
}

FunctionTemplate

• Can resolve template parameters using auto deduction or implicit casts
• Prioritizes matching function that already exist instead of instantiating a template
• Supports function templates within a record

Example:

(ObjectType int removed for better visualization)

template <class T=int, int N=5>
T fixed_multiply (T val)
{
  auto x = val * N;
  return x;
}

int main() {
  fixed_multiply<int,2>(10);
}

Future Changes

There are some request that weren't addressed in this PR, but we will have to take care of them in the future:

• Add Support for Template Specialization
• Add TemplateExpansionPass to realize every template instantiation

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!

0 Bugs
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54 Code Smells

82.8% Coverage
0.0% Duplication