capture functionality behind a define switch: TM_ENABLE_CAPTURED_LAMBDAS

Author: dave

README.md

@@ -38,7 +38,11 @@ In the setup method, add an function callback that gets fired once in the future
 	}, TIME_SECONDS);
 ```
 
-From 1.2 onwards: On ESP8266, ESP32, all mbed boards, and most 32 bit Arduino boards you can also capture values. An example of this usage follows:
+From 1.2 onwards: On ESP8266, ESP32, all mbed boards, and most 32 bit Arduino boards you can also *enable* argument capture in lambda expressions. By default, the feature is off because it is quite a heavy feature that many may never use.
+
+To enable set add the following flag to your compile options, and it will be enabled if the board supports it: `-DTM_ENABLE_CAPTURED_LAMBDAS`
+
+An example of this usage follows:
 
 ```
     int capturedValue = 42;

src/TaskPlatformDeps.h

@@ -11,7 +11,7 @@ class TimerTask;
 
 #if defined(__MBED__) || defined(ARDUINO_ARDUINO_NANO33BLE)
 
-#if !defined(TM_DONT_USE_CAPTURE)
+#if defined(TM_ENABLE_CAPTURED_LAMBDAS)
 #define TM_ALLOW_CAPTURED_LAMBDA
 #endif
 
@@ -89,7 +89,7 @@ namespace tm_internal {
 #include "Arduino.h"
 typedef uint8_t pintype_t;
 # define IOA_USE_ARDUINO
-#if !defined(TM_DONT_USE_CAPTURE)
+#if defined(TM_ENABLE_CAPTURED_LAMBDAS)
 # define TM_ALLOW_CAPTURED_LAMBDA
 #endif
 
@@ -273,7 +273,7 @@ inline void atomicWritePtr(TimerTaskAtomicPtr* pPtr, TimerTask* newValue) {
 
 // for all mbed and ESP boards we already enable lambda captures, SAMD is a known extra case that works.
 // we can only enable on larger boards with enough memory to take the extra size of the structures.
-#if !defined(TM_DONT_USE_CAPTURE) && defined(ARDUINO_ARCH_SAMD)
+#if defined(TM_ENABLE_CAPTURED_LAMBDAS) && defined(ARDUINO_ARCH_SAMD)
 # define TM_ALLOW_CAPTURED_LAMBDA
 #endif
 
@@ -357,7 +357,7 @@ namespace tm_internal {
 // Here we have one last go at determining if we should enable capture lambdas by checking if the functional include
 // is available, we only do so if we are on GCC > 5
 //
-# if !defined(TM_ALLOW_CAPTURED_LAMBDA) && !defined(TM_DONT_USE_CAPTURE) && __GNUC__ >= 5
+# if !defined(TM_ALLOW_CAPTURED_LAMBDA) && defined(TM_ENABLE_CAPTURED_LAMBDAS) && __GNUC__ >= 5
 #if __has_include(<functional>)
 # define TM_ALLOW_CAPTURED_LAMBDA
 #endif // _has_include