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This video, I want to again show you a very useful command that we can use inside GDP when you're looking

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at a program or debating it.

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Again, we're going to compile with the Dashty for debarking symbols and run our program within GDP

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here and around the array of this program again.

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And I'm going to start it and I'm going to walk through it a few times through this insert and then

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step into our insert function and listed it out here in the Hashmat insert function.

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So at this point, let's walk through a few different commands.

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And interestingly, I see that we are working with this new pair.

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Very well, and I see that it's here, but let's say we want to know what the particular type is because

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you're debugging and you're really deep inside the code.

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For instance, we can actually do something very interesting, which is just to type what is new pair,

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and that'll actually confirm that the type is in fact a pair underscore T and star.

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That's a pair underscore t pointer, which matches what we see in our source code here.

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So if it happens that this variable is declared in the line right above us, that's fine.

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But if we don't know what the type is, we can just type what is.

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What also is means is we can use what is for other things like hash map, insert, for instance, which

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is the function that we're executing.

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So actually give us the type of this function which returns void matches what we see at line 61 and

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shows us the inputs into this function.

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So we're using more complicated structures like function pointers.

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This will help us out.

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So if I scroll up here.

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I will actually notice that when I create a hash map, I have a hash function here, so let's see if

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we can figure out what that is.

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So what is?

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Well, in all of our hash maps we have and so let's make sure that it is, in fact, a hash map.

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And it is so.

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It is.

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So what is in and we want to know what the hash functions.

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And it says that the type is hash function pointer.

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OK, so let's find out what hash function pointer is in our code and using them or your code editor,

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you can look for it manually and just type it in hash function where let's search for it and we find

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it here.

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There's actually a typed definition.

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And this, our hash function pointer is something that returns an integer, takes in a charge, star

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it.

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So this is pretty neat that we can figure out what the types are.

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Things even like function pointers and GDB again, can save us a lot of time by just again looking at

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the code that we're around and querying what the variable types are, what the struct types are, what

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the functions are, for example.

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So what is, is a really useful tool.