udpated type conversion function definitions, added note to toDuration, resolves #315

content/v2.0/reference/flux/functions/built-in/transformations/type-conversions/tobool.md

@@ -22,7 +22,7 @@ toBool()
 {{% note %}}
 To convert values in a column other than `_value`, define a custom function
 patterned after the [function definition](#function-definition),
-but replace the column in the `bool()` function with your desired column.
+but replace `_value` with your desired column.
 {{% /note %}}
 
 ## Examples
@@ -39,7 +39,7 @@ from(bucket: "telegraf")
 ```js
 toBool = (tables=<-) =>
   tables
-    |> map(fn:(r) => bool(v: r._value))
+    |> map(fn:(r) => ({ r with _value: bool(v: r._value) }))
 ```
 
 _**Used functions:**

content/v2.0/reference/flux/functions/built-in/transformations/type-conversions/toduration.md

@@ -10,6 +10,10 @@ menu:
 weight: 501
 ---
 
+{{% warn %}}
+**`toDuration()` was removed in Flux 0.37.**
+{{% /warn %}}
+
 The `toDuration()` function converts all values in the `_value` column to durations.
 
 _**Function type:** Type conversion_  
@@ -22,7 +26,7 @@ toDuration()
 {{% note %}}
 To convert values in a column other than `_value`, define a custom function
 patterned after the [function definition](#function-definition),
-but replace the column in the `duration()` function with your desired column.
+but replace `_value` with your desired column.
 {{% /note %}}
 
 ## Examples
@@ -39,7 +43,7 @@ from(bucket: "telegraf")
 ```js
 toDuration = (tables=<-) =>
   tables
-    |> map(fn:(r) => duration(v: r._value))
+    |> map(fn:(r) => ({ r with _value: duration(v: r._value) }))
 ```
 
 _**Used functions:**

content/v2.0/reference/flux/functions/built-in/transformations/type-conversions/tofloat.md

@@ -22,7 +22,7 @@ toFloat()
 {{% note %}}
 To convert values in a column other than `_value`, define a custom function
 patterned after the [function definition](#function-definition),
-but replace the column in the `float()` function with your desired column.
+but replace `_value` with your desired column.
 {{% /note %}}
 
 ## Examples
@@ -39,7 +39,7 @@ from(bucket: "telegraf")
 ```js
 toFloat = (tables=<-) =>
   tables
-    |> map(fn:(r) => float(v: r._value))
+    |> map(fn:(r) => ({ r with _value: float(v: r._value) }))
 ```
 
 _**Used functions:**

content/v2.0/reference/flux/functions/built-in/transformations/type-conversions/toint.md

@@ -22,7 +22,7 @@ toInt()
 {{% note %}}
 To convert values in a column other than `_value`, define a custom function
 patterned after the [function definition](#function-definition),
-but replace the column in the `int()` function with your desired column.
+but replace `_value` with your desired column.
 {{% /note %}}
 
 ## Examples
@@ -39,7 +39,7 @@ from(bucket: "telegraf")
 ```js
 toInt = (tables=<-) =>
   tables
-    |> map(fn:(r) => int(v: r._value))
+    |> map(fn:(r) => ({ r with _value: int(v: r._value) }))
 ```
 
 _**Used functions:**

content/v2.0/reference/flux/functions/built-in/transformations/type-conversions/tostring.md

@@ -22,7 +22,7 @@ toString()
 {{% note %}}
 To convert values in a column other than `_value`, define a custom function
 patterned after the [function definition](#function-definition),
-but replace the column in the `string()` function with your desired column.
+but replace `_value` with your desired column.
 {{% /note %}}
 
 ## Examples
@@ -39,7 +39,7 @@ from(bucket: "telegraf")
 ```js
 toString = (tables=<-) =>
   tables
-    |> map(fn:(r) => string(v: r._value))
+    |> map(fn:(r) => ({ r with _value: string(v: r._value) }))
 ```
 
 _**Used functions:**

content/v2.0/reference/flux/functions/built-in/transformations/type-conversions/totime.md

@@ -22,7 +22,7 @@ toTime()
 {{% note %}}
 To convert values in a column other than `_value`, define a custom function
 patterned after the [function definition](#function-definition),
-but replace the column in the `time()` function with your desired column.
+but replace `_value` with your desired column.
 {{% /note %}}
 
 ## Examples
@@ -39,7 +39,7 @@ from(bucket: "telegraf")
 ```js
 toTime = (tables=<-) =>
   tables
-    |> map(fn:(r) => time(v:r._value))
+    |> map(fn:(r) => ({ r with _value: time(v:r._value) }))
 ```
 
 _**Used functions:**

content/v2.0/reference/flux/functions/built-in/transformations/type-conversions/touint.md

@@ -22,7 +22,7 @@ toUInt()
 {{% note %}}
 To convert values in a column other than `_value`, define a custom function
 patterned after the [function definition](#function-definition),
-but replace the column in the `uint()` function with your desired column.
+but replace `_value` with your desired column.
 {{% /note %}}
 
 ## Examples
@@ -39,7 +39,7 @@ from(bucket: "telegraf")
 ```js
 toUInt = (tables=<-) =>
   tables
-    |> map(fn:(r) => uint(v:r._value))
+    |> map(fn:(r) => ({ r with _value: uint(v:r._value) }))
 ```
 
 _**Used functions:**