ContextOperator.Inject: key is not comparable

[kozmod]

Description

BUG:
default ContextOperator use database (TxBeginner) for extracting and injecting ( Inject/Extract) transaction (Tx) to context.Context:

// ContextOperator inject and extract Tx from context.Context.
type ContextOperator[B any 👈🏻 , T Tx] struct {
	beginner *B
}

// NewContextOperator returns new ContextOperator.
func NewContextOperator[B any, T Tx](b *B) *ContextOperator[B, T] {
	return &ContextOperator[B, T]{
		beginner: b,
	}
}

// Inject returns new context.Context contains Tx as value.
func (p *ContextOperator[B, T]) Inject(ctx context.Context, tx T) context.Context {
	return context.WithValue(ctx, p.beginner, tx) 👈🏻
}

// Extract returns Tx extracted from context.Context.
func (p *ContextOperator[B, T]) Extract(ctx context.Context) (T, bool) {
	c, ok := ctx.Value(p.beginner).(T) 👈🏻
	return c, ok
}

if type B is not comparable, context.Context produce the panic: " key is not comparable"

To avoid the produce, need to change type B to comparable:

// ContextOperator inject and extract Tx from context.Context.
type ContextOperator[B comparable, T Tx] struct {
	beginner B
}

// NewContextOperator returns new ContextOperator.
func NewContextOperator[B comparable, T Tx](b B) *ContextOperator[B, T] {
	return &ContextOperator[B, T]{
		beginner: b,
	}
}

ENCHANCEMENT:
default ContextOperator use *B type in the constructor. It's a bit unhandy.

// NewContextOperator returns new ContextOperator.
func NewContextOperator[B any, T Tx](b *B 👈🏻) *ContextOperator[B, T] {
	return &ContextOperator[B, T]{
		beginner: b,
	}
}

the pointer may be removed.