4.8 KiB
| title | TARGET DECK | FILE TAGS | tags | |
|---|---|---|---|---|
| Typedefs | Obsidian::STEM | c17::type |
|
Overview
The <stddef.h> header defines a few standard typedefs:
ptrdiff_t: the signed integer type of the result of subtracting two pointers.size_t: the unsigned integer type of the result of thesizeofoperator.
The standard often uses typedefs ending with _t.
%%ANKI
Basic
What is the type of x in the following?
#define int_ptr int *
int_ptr x, y;
Back: int *
Reference: Van der Linden, Peter. Expert C Programming: Deep C Secrets. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
END%%
%%ANKI
Basic
What is the type of y in the following?
#define int_ptr int *
int_ptr x, y;
Back: int
Reference: Van der Linden, Peter. Expert C Programming: Deep C Secrets. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
END%%
%%ANKI
Basic
What is the type of x in the following?
typedef int_ptr int *
int_ptr x, y;
Back: int *
Reference: Van der Linden, Peter. Expert C Programming: Deep C Secrets. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
END%%
%%ANKI
Basic
What is the type of y in the following?
typedef int_ptr int *
int_ptr x, y;
Back: int *
Reference: Van der Linden, Peter. Expert C Programming: Deep C Secrets. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.
END%%
%%ANKI
Basic
What header defines size_t?
Back: <stddef.h>
Reference: “ISO: Programming Languages - C17,” April 2017, https://www.open-std.org/jtc1/sc22/wg14/www/abq/c17_updated_proposed_fdis.pdf.
END%%
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Basic
What header defines ptrdiff_t?
Back: <stddef.h>
Reference: “ISO: Programming Languages - C17,” April 2017, https://www.open-std.org/jtc1/sc22/wg14/www/abq/c17_updated_proposed_fdis.pdf.
END%%
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Basic
ptrdiff_t is used as the type of what result?
Back: Subtracting two pointers.
Reference: “ISO: Programming Languages - C17,” April 2017, https://www.open-std.org/jtc1/sc22/wg14/www/abq/c17_updated_proposed_fdis.pdf.
END%%
%%ANKI
Basic
size_t is used as the type of what result?
Back: The sizeof operation.
Reference: “ISO: Programming Languages - C17,” April 2017, https://www.open-std.org/jtc1/sc22/wg14/www/abq/c17_updated_proposed_fdis.pdf.
END%%
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Basic
Is ptrdiff_t signed or unsigned?
Back: Signed.
Reference: “ISO: Programming Languages - C17,” April 2017, https://www.open-std.org/jtc1/sc22/wg14/www/abq/c17_updated_proposed_fdis.pdf.
END%%
%%ANKI Basic When can two pointers be subtracted? Back: Only if both refer to elements of the same array object. Reference: Jens Gustedt, Modern C (Shelter Island, NY: Manning Publications Co, 2020).
END%%
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Basic
What is the result of p - q in the following?
double A[4] = { 0.0, 1.0, 2.0, -3.0 };
double* p = &A[1];
double* q = &A[3];
Back: -2
Reference: Jens Gustedt, Modern C (Shelter Island, NY: Manning Publications Co, 2020).
END%%
%%ANKI
Basic
What is the result of p - q in the following?
double A[4] = { 0.0, 1.0, 2.0, -3.0 };
double* p = &A[3];
double* q = &A[1];
Back: 2
Reference: Jens Gustedt, Modern C (Shelter Island, NY: Manning Publications Co, 2020).
END%%
%%ANKI
Basic
Is size_t signed or unsigned?
Back: Unsigned.
Reference: “ISO: Programming Languages - C17,” April 2017, https://www.open-std.org/jtc1/sc22/wg14/www/abq/c17_updated_proposed_fdis.pdf.
END%%
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Basic
The C standard typically suffixes typedefs with what?
Back: _t
Reference: Jens Gustedt, Modern C (Shelter Island, NY: Manning Publications Co, 2020).
END%%
Bibliography
- “ISO: Programming Languages - C17,” April 2017, https://www.open-std.org/jtc1/sc22/wg14/www/abq/c17_updated_proposed_fdis.pdf.
- Jens Gustedt, Modern C (Shelter Island, NY: Manning Publications Co, 2020).
- Van der Linden, Peter. Expert C Programming: Deep C Secrets. Programming Languages / C. Mountain View, Cal.: SunSoft Pr, 1994.