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Updated Examples and Recipes (markdown)

Howard Hinnant
2016-05-21 11:34:55 -04:00
parent cae3ae8f35
commit d9063e5ce1
1 changed files with 9 additions and 9 deletions
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Examples-and-Recipes.md

@@ -225,12 +225,12 @@ This creates two `year_month` objects and subtracts them. This gives a `std::ch
36 36
To include the influence of the day-fields, it is best to convert `d1` and `d2` to `sys_days `s: To include the influence of the day-fields, it is best to convert `d1` and `d2` to `sys_days`s:
auto dp1 = sys_days(d1); auto dp1 = sys_days(d1);
auto dp2 = sys_days(d2); auto dp2 = sys_days(d2);
Now we could (for example) subtract the two `sys_days `s, and round the result to the nearest integral month: Now we could (for example) subtract the two `sys_days`s, and round the result to the nearest integral month:
std::cout << round<months>(dp2-dp1).count() << '\n'; std::cout << round<months>(dp2-dp1).count() << '\n';
@@ -259,11 +259,11 @@ The [ISO week date](https://en.wikipedia.org/wiki/ISO_week_date) is an internati
Like `<date.h>`, you can specify an ISO week date in any of the three orders: y/wn/wd, wd/wn/y, wn/wd/y (big endian, little endian, mixed (american) endian). Like `<date.h>`, you can specify an ISO week date in any of the three orders: y/wn/wd, wd/wn/y, wn/wd/y (big endian, little endian, mixed (american) endian).
Also like `<date.h>`, you can implicitly convert a ISO week date to `sys_days `, and vice-versa. For convenience, an alias of `date:: sys_days ` exists as `iso_week:: sys_days `: Also like `<date.h>`, you can implicitly convert a ISO week date to `sys_days`, and vice-versa. For convenience, an alias of `date:: sys_days ` exists as `iso_week:: sys_days `:
iso_week:: sys_days dp = iso_date; iso_week:: sys_days dp = iso_date;
And recall that `sys_days ` is just a type alias for a `std::chrono::time_point<std::chrono::system_clock, days>`. So the ISO week date (`iso_week:year_weeknum_weekday`) is immediately interoperable with the entire `<chrono>` library, just like `date::year_month_day` is. And recall that `sys_days` is just a type alias for a `std::chrono::time_point<std::chrono::system_clock, days>`. So the ISO week date (`iso_week:year_weeknum_weekday`) is immediately interoperable with the entire `<chrono>` library, just like `date::year_month_day` is.
auto now = std::chrono::system_clock::now(); auto now = std::chrono::system_clock::now();
auto dp = date::floor<iso_week::days>(now); auto dp = date::floor<iso_week::days>(now);
@@ -275,7 +275,7 @@ Which just output for me:
2016-W11-Sat 03:07:02.460737 2016-W11-Sat 03:07:02.460737
And because `iso_week:year_weeknum_weekday` is implicitly convertible to and from `sys_days `, that makes it immediately (and explicitly) convertible to any other calendar system that is implicitly convertible to and from `sys_days `: And because `iso_week:year_weeknum_weekday` is implicitly convertible to and from `sys_days`, that makes it immediately (and explicitly) convertible to any other calendar system that is implicitly convertible to and from `sys_days`:
auto civil_date = date::year_month_day{iso_date}; auto civil_date = date::year_month_day{iso_date};
std::cout << civil_date << ' ' << time << '\n'; std::cout << civil_date << ' ' << time << '\n';
@@ -284,7 +284,7 @@ which outputs:
2016-03-19 03:07:02.460737 2016-03-19 03:07:02.460737
And there you have it: `sys_days ` is a _Rosetta Stone_ for translating _any_ calendar to any other calendar. Just make your calendar convert to and from `sys_days `, and you have interoperability with _every_ other calendar which does so. And there you have it: `sys_days` is a _Rosetta Stone_ for translating _any_ calendar to any other calendar. Just make your calendar convert to and from `sys_days`, and you have interoperability with _every_ other calendar which does so.
using namespace date::literals; using namespace date::literals;
auto today = 2016_y/mar/19; auto today = 2016_y/mar/19;
@@ -381,7 +381,7 @@ Let's say you want to search the globe, and all time, for time zones when the da
auto end = sys_days{jan/1/2035} + 0s; auto end = sys_days{jan/1/2035} + 0s;
do do
{ {
auto info = z.get_info(begin, tz::utc); auto info = z.get_info(begin);
if (info.save != 0h && info.save != 1h) if (info.save != 0h && info.save != 1h)
{ {
std::cout << z.name() << " has a daylight savings offset of " std::cout << z.name() << " has a daylight savings offset of "
@@ -396,9 +396,9 @@ Let's say you want to search the globe, and all time, for time zones when the da
You first get a reference to the tz database, then iterate over each zone in the database. For each zone, set a range of time points to search over. In this example I start searching as far back as possible, and search forward to the year 2035. You first get a reference to the tz database, then iterate over each zone in the database. For each zone, set a range of time points to search over. In this example I start searching as far back as possible, and search forward to the year 2035.
Starting at the beginning of time, get an `Info` for that UTC `time_point`. An `Info` looks like this: Starting at the beginning of time, get an `sys_info` for that UTC `time_point`. An `sys_info` looks like this:
struct Info struct sys_info
{ {
second_point begin; second_point begin;
second_point end; second_point end;